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11P06

Work, Energy and Power

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11P06.1

Scalar Product and Work

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11P06.1 Scalar Product and Work

Learning Objectives

Scalar Product

Work

Conservative and Non Conservative Force

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11P06.1

CV 1

Scalar Product

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11P06.1 Work

Scalar Product

Multiplication of Vector

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11P06.1 Work

Scalar Product

Multiplication of Vector

With Scalar Quantity

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11P06.1 Work

Scalar Product

Multiplication of Vector

With Scalar Quantity

With Vector Quantity

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11P06.1 Work

Scalar Product

Multiplication of Vector

With Scalar Quantity

With Vector Quantity

Dot/Scalar Product

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11P06.1 Work

Scalar Product

Multiplication of Vector

With Scalar Quantity

With Vector Quantity

Dot/Scalar Product

Denoted by (•)

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11P06.1 Work

Scalar Product

Multiplication of Vector

With Scalar Quantity

With Vector Quantity

Dot/Scalar Product

Cross Product

Denoted by (•)

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11P06.1 Work

Scalar Product

Multiplication of Vector

With Scalar Quantity

With Vector Quantity

Dot/Scalar Product

Cross Product

Denoted by (•)

Denoted by ( ╳ )

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

Scalar Quantity

θ

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Scalar Product

Geometrical meaning of Dot Product:

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Scalar Product

Geometrical meaning of Dot Product:

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Scalar Product

Geometrical meaning of Dot Product:

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ConcepTest

Ready for challenge

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11P06.1 Work

Scalar Product

Question:

Solution:

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Pause the Video

(Time Duration : 2 Minutes)

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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ConcepTest

Ready for challenge

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11P06.1 Work

Scalar Product

Question:

Solution:

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Pause the Video

(Time Duration : 2 Minutes)

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

When vectors are given in component form

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

When vectors are given in component form

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

When vectors are given in component form

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

When vectors are given in component form

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

When vectors are given in component form

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

When vectors are given in component form

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11P06.1 Work

Scalar Product

Scalar Product/Dot product:

When vectors are given in component form

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ConcepTest

Ready for challenge

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11P06.1 Work

Scalar Product

Question:

Solution:

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Pause the Video

(Time Duration : 3 Minutes)

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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11P06.1 Work

Scalar Product

Question:

Solution:

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Scalar Product

Properties of Scalar Product:

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Scalar Product

Properties of Scalar Product:

  • Z

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Scalar Product

Properties of Scalar Product:

  • Z

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Scalar Product

Properties of Scalar Product:

  • Z

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Scalar Product

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CV-2

Work

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Work

What is the work?

You are solving your homework problem in your mind

Is this a work ?

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Work

What is the work?

A person carries buckets of water along a horizontal path while walking at constant velocity.

Is he doing Work?

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Work

What is the work?

A Man holds a chair at arm’s length for several minutes.

Is he doing Work?

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Work

What is the work?

No, These all are not doing any work according to the language of science

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11P06.1 Work

Work

What is the work?

Work is said to be done when a force is applied on an object and there is a displacement of the point of application in the direction of the force or in the direction other than 90 degrees with the direction of force.

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11P06.1 Work

Work

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11P06.1 Work

Work

Work is a Vector Quantity or a Scalar Quantity?

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11P06.1 Work

Work

Work is a Scalar Quantity

Work is a Vector Quantity or a Scalar Quantity?

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11P06.1 Work

Work

What is the Unit and Dimension of Work ?

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11P06.1 Work

Work

What is the Unit and Dimension of Work ?

Unit of work is N-m or Joule(J)

Dimension of work is [ML2T-2]

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11P06.1 Work

Work

Nature of Work

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11P06.1 Work

Work

0° ≤ θ < 90° cosθ>0

Nature of Work

Positive Work

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11P06.1 Work

Work

Nature of Work

Negative Work

180°≥θ>90° cosθ<0

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11P06.1 Work

Work

Nature of Work

Zero Work

Displacement = 0

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11P06.1 Work

Work

Nature of Work

Zero Work

Displacement = 0

or θ = 90° cosθ=0

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ConcepTest

Ready for challenge

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11P06.1 Work

Work

Example: A Force of 15 N at angle 600 from horizontal is used to push a box along

the floor a distance of 3 meters. How much work was done?

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Pause the Video

(Time Duration : 2 Minutes)

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11P06.1 Work

Work

Example: A Force of 15 N at angle 600 from horizontal is used to push a box along

the floor a distance of 3 meters. How much work was done?

Solution:

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11P06.1 Work

Work

Example: A Force of 15 N at angle 600 from horizontal is used to push a box along

the floor a distance of 3 meters. How much work was done?

Solution:

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CV-3

Work Done by Variable Force

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11P06.1 Work

Variable Force

Variable:Quantity Which changes with respect to any other quantity

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11P06.1 Work

Variable Force

Variable Force: when magnitude or direction of force changes with time or displacement

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11P06.1 Work

Variable Force

Variable Force: when magnitude or direction of force changes with time or displacement

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11P06.1 Work

Variable Force

Variable Force: when magnitude or direction of force changes with time or displacement

F

t

F

X

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11P06.1 Work

Work

Spring Force

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11P06.1 Work

Work

Spring Force

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11P06.1 Work

Work

Spring Force

(Hooke’s Law)

k = spring constant

k ∝ stiffness of spring

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11P06.1 Work

Work

Spring Force

(Hooke’s Law)

k = spring constant

k ∝ stiffness of spring

FS

X

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11P06.1 Work

Work done by a variable Force

Work done by a variable Force:

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11P06.1 Work

Work

Work done by a variable Force

Work done by a variable Force:

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11P06.1 Work

Work

Work done by a variable Force

Work done by a variable Force:

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11P06.1 Work

Work

Work done by a variable Force

Work done by a variable Force:

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11P06.1 Work

Work

Work done by a variable Force

Work done by a variable Force:

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11P06.1 Work

Work

Work done by a variable Force

Work done by Spring:

FE

FS

xm

x=0

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11P06.1 Work

Work

Work done by a variable Force

Work done by Spring:

FE

FS

xm

x=0

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11P06.1 Work

Work

Work done by a variable Force

Work done by Spring:

FE

FS

xm

x=0

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11P06.1 Work

Work

Work done by a variable Force

Work done by Spring:

FE

FS

xm

x=0

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11P06.1 Work

Work

Work done by a variable Force

Work done by Spring:

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ConcepTest

Ready for challenge

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11P06.1 Work

Work

Work done by a variable Force

Question: Figure show the force F (in newton) acting on a body as a function of x.

Calculate the work done in moving the body from x = 0 to x = 4 m.

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Pause the Video

(Time Duration : 3 Minutes)

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11P06.1 Work

Work

Work done by a variable Force

Question: Figure show the force F (in newton) acting on a body as a function of x.

Calculate the work done in moving the body from x = 0 to x = 4 m.

Solution:

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11P06.1 Work

Work

Work done by a variable Force

Question: Figure show the force F (in newton) acting on a body as a function of x.

Calculate the work done in moving the body from x = 0 to x = 4 m.

Solution:

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11P06.1 Work

Work

Work done by a variable Force

Question: Figure show the force F (in newton) acting on a body as a function of x.

Calculate the work done in moving the body from x = 0 to x = 4 m.

Solution:

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11P06.1 Work

Work

Work done by a variable Force

Question: Figure show the force F (in newton) acting on a body as a function of x.

Calculate the work done in moving the body from x = 0 to x = 4 m.

Solution:

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11P06.1 Work

Work

Work done by a variable Force

Question: Figure show the force F (in newton) acting on a body as a function of x.

Calculate the work done in moving the body from x = 0 to x = 4 m.

Solution:

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ConcepTest

Ready for challenge

108 of 413

11P06.1 Work

Work

Work done by a variable Force

Question: A force is given by function F=x2 calculate the work done by it for

displacement of body from x=3 to x=9.

Solution:

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Pause the Video

(Time Duration : 3 Minutes)

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11P06.1 Work

Work

Work done by a variable Force

Question: A force is given by function F=x2 calculate the work done by it for

displacement of body from x=3 to x=9.

Solution:

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11P06.1 Work

Work

Work done by a variable Force

Question: A force is given by function F=x2 calculate the work done by it for

displacement of body from x=3 to x=9.

Solution:

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11P06.1 Work

Work

Work done by a variable Force

Question: A force is given by function F=x2 calculate the work done by it for

displacement of body from x=3 to x=9.

Solution:

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CV-4

Conservative and Non-Conservative Force

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11P06.1 Work

Conservative and Non-Conservative Force

Conservative Force

Work done depends only on initial and final position of object.

Example:Gravitational force,Spring Force

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11P06.1 Work

Conservative and Non-Conservative Force

Conservative Force

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11P06.1 Work

Conservative and Non-Conservative Force

f

Work done depends on path rather than initial and final positions of objects.

Example:Friction force

Non-Conservative Force

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11P06.1 Work

Conservative and Non-Conservative Force

Non-Conservative Force

f

f

f

Work done depends on path rather than initial and final positions of objects.

Example:Friction force

f

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11P06.1 Work

Conservative and Non-Conservative Force

Non-Conservative Force

f

f

f

Work done depends on path

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11P06.1 Work

Conservative and Non-Conservative Force

Non-Conservative Force

f

f

f

Work done depends on path

f

|Wf(ACB)| >|Wf(AB)|

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ConcepTest

Ready for challenge

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11P06.1 Work

Conservative and Non-Conservative Force

Question: A ball of mass m is thrown upwards from ground calculate the total work

done by gravity when it reaches back to the ground.

Solution:

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Pause the Video

(Time Duration : 1 Minutes)

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11P06.1 Work

Conservative and Non-Conservative Force

Question: A ball of mass m is thrown upwards from ground calculate the total work

done by gravity when it reaches back to the ground.

Solution: Gravity is a conservative force so for same initial and final point the total

work done by it will be zero.

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11P06.1 Work

Conservative and Non-Conservative Force

Question: A ball of mass m is thrown upwards from ground calculate the total work

done by gravity when it reaches back to the ground.

Solution: Gravity is a conservative force so for same initial and final point the total

work done by it will be zero.

Or

Suppose ball went a height H upwards

Work done by gravity when ball is

Going upward

Work done by gravity when ball is

coming downward

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ConcepTest

Ready for challenge

126 of 413

11P06.1 Work

Conservative and Non-Conservative Force

Question: Calculate the work done by friction when a box of mass 10 kg is moved

from A to B by Path AB and ACDB. 𝜇 for the surface is 0.2.

Take g=10 ms-2 .

Solution:

A

B

D

C

4 m

4 m

4 m

4 m

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11P06.1 Work

Conservative and Non-Conservative Force

Question: Calculate the work done by friction when a box of mass 10 kg is moved

from A to B by Path AB and ACDB. 𝜇 for the surface is 0.2.

Take g=10 ms-2 .

Solution:

A

B

D

C

4 m

4 m

4 m

4 m

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Pause the Video

(Time Duration : 3 Minutes)

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11P06.1 Work

Conservative and Non-Conservative Force

Question: Calculate the work done by friction when a box of mass 10 kg is moved

from A to B by Path AB and ACDB. 𝜇 for the surface is 0.2.

Take g=10 ms-2 .

Solution:

A

B

D

C

4 m

4 m

4 m

4 m

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11P06.1 Work

Conservative and Non-Conservative Force

Question: Calculate the work done by friction when a box of mass 10 kg is moved

from A to B by Path AB and ACDB. 𝜇 for the surface is 0.2.

Take g=10 ms-2 .

Solution:

A

B

D

C

4 m

4 m

4 m

4 m

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11P06.1 Work

Conservative and Non-Conservative Force

Question: Calculate the work done by friction when a box of mass 10 kg is moved

from A to B by Path AB and ACDB. 𝜇 for the surface is 0.2.

Take g=10 ms-2 .

Solution:

A

B

D

C

4 m

4 m

4 m

4 m

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11P06.1 Work

11P06.1 Summary

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PSV 1

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11P06.1 Scalar Product and Work

Question: A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (a) work done by the applied force in 10 s

(b) work done by friction in 10 s

(c) work done by the net force on the body in 10 s.

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11P06.1 Work

11P06.1 Scalar Product and Work

Question: A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (a) work done by the applied force in 10 s.

Solution:

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11P06.1 Work

11P06.1 Scalar Product and Work

Question: A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (a) work done by the applied force in 10 s.

Solution:

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11P06.1 Work

11P06.1 Scalar Product and Work

Question: A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (a) work done by the applied force in 10 s.

Solution:

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11P06.1 Work

11P06.1 Scalar Product and Work

Question: A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (a) work done by the applied force in 10 s.

Solution:

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11P06.1 Work

11P06.1 Scalar Product and Work

Question: A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (a) work done by the applied force in 10 s.

Solution:

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11P06.1 Work

11P06.1 Scalar Product and Work

Question: A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (a) work done by the applied force in 10 s.

Solution:

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11P06.1 Work

11P06.1 Scalar Product and Work

Question:A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (a) work done by the applied force in 10 s

Solution: (a)

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11P06.1 Work

11P06.1 Scalar Product and Work

Question:A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (b) work done by friction in 10 s

Solution: (b)

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11P06.1 Work

11P06.1 Scalar Product and Work

Question:A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (c) work done by the net force on the body in 10 s.

Solution: (c)

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11P06.1 Work

11P06.1 Scalar Product and Work

Question:A body of mass 2 kg initially at rest moves under the action of an applied

horizontal force of 7 N on a table with coefficient of kinetic friction = 0.1

Compute the (c) work done by the net force on the body in 10 s.

Solution: (c)

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11P06.2

Energy

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11P06.2 Energy

Learning Objectives

Introduction to Energy

Forms of Energy

Kinetic Energy

Potential Energy

Conservation of Energy

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CV-1

Introduction to Energy

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Energy

Energy

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Energy

Energy

Capacity of Doing Work or cause change

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Energy

Energy

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Energy

An object which does work losses energy

Energy

Capacity of Doing Work or cause change

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Energy

An object which does work losses energy

Energy

An object on which work is done gains Energy

Capacity of Doing Work or cause change

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Energy

Energy

Capacity of Doing Work

Work

Transfer of Energy

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Energy

Energy

Capacity of Doing Work

Work

Transfer of Energy

Unit of Energy= Unit of Work=Joule(J)

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CV-2

Forms of Energy

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11P06.2 Energy

Energy

Forms of Energy

Electrical Energy

Heat Energy

Chemical Energy

Nuclear Energy

Mechanical Energy

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11P06.2 Energy

Energy

Electrical Energy

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11P06.2 Energy

Energy

Chemical Energy

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11P06.2 Energy

Energy

Heat Energy

Steam Engine

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11P06.2 Energy

Energy

Nuclear Energy

Nuclear Power Plant

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11P06.2 Energy

Energy

Mechanical Energy

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11P06.2 Energy

Energy

Mechanical Energy

It is energy in an object due to its motion or position.

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11P06.2 Energy

Energy

Mechanical Energy

Kinetic Energy

Potential Energy

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CV-3

Kinetic Energy

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Kinetic Energy

Kinetic Energy:

Energy of a body by virtue of its motion

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Kinetic Energy

Kinetic Energy:

Energy of a body by virtue of its motion

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Kinetic Energy

Kinetic Energy:

Energy of a body by virtue of its motion

If an object is moving, then it is capable of doing work. It has energy of motion, or kinetic energy (KE)

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Kinetic Energy

Kinetic Energy:

Energy of a body by virtue of its motion

If an object is moving, then it is capable of doing work. It has energy of motion, or kinetic energy (KE)

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

The net work done on an object is equal to its change in kinetic energy (W = KEf – KEi)

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

The net work done on an object is equal to its change in kinetic energy (W = KEf – KEi)

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

m

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

m

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

m

m

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

m

m

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

m

m

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11P06.2 Energy

Kinetic Energy

Work Energy Theorem:

m

m

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ConcepTest

Ready for challenge

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11P06.2 Energy

Kinetic Energy

Question:A locomotive weighing 106 kg starts from rest and moves with a

constant acceleration of 0.5 m/s2. After travelling a distance of 900 m on

the track, what is the kinetic energy of the locomotive?

Solution:

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Pause the Video

(Time Duration : 2 Minutes)

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11P06.2 Energy

Kinetic Energy

Question:A locomotive weighing 106 kg starts from rest and moves with a

constant acceleration of 0.5 m/s2. After travelling a distance of 900 m on

the track, what is the kinetic energy of the locomotive?

Solution:

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11P06.2 Energy

Kinetic Energy

Question:A locomotive weighing 106 kg starts from rest and moves with a

constant acceleration of 0.5 m/s2. After travelling a distance of 900 m on

the track, what is the kinetic energy of the locomotive?

Solution:

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11P06.2 Energy

Kinetic Energy

Question:A locomotive weighing 106 kg starts from rest and moves with a

constant acceleration of 0.5 m/s2. After travelling a distance of 900 m on

the track, what is the kinetic energy of the locomotive?

Solution:

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11P06.2 Energy

Kinetic Energy

Question:A locomotive weighing 106 kg starts from rest and moves with a

constant acceleration of 0.5 m/s2. After travelling a distance of 900 m on

the track, what is the kinetic energy of the locomotive?

Solution:

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ConcepTest

Ready for challenge

191 of 413

11P06.2 Energy

Kinetic Energy

Question:A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches

the bottom if the incline is smooth?

Solution:

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Pause the Video

(Time Duration : 2 Minutes)

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11P06.2 Energy

Kinetic Energy

Question:A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches

the bottom if the incline is smooth?

Solution: Work done by the forces N and, which

are normal to the surface, is zero.

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11P06.2 Energy

Kinetic Energy

Question:A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches

the bottom if the incline is smooth?

Solution: Work done by the forces N and, which

are normal to the surface, is zero.

Work done by the force mg sin θ =

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11P06.2 Energy

Kinetic Energy

Question:A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches

the bottom if the incline is smooth?

Solution: Work done by the forces N and, which

are normal to the surface, is zero.

Work done by the force mg sin θ =

Work = change in kinetic energy

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CV-4

Potential Energy

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Potential Energy

Stored energy that results from the position or shape of an object is called Potential Energy

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Potential Energy

Stored energy that results from the position or shape of an object is called Potential Energy

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Potential Energy

Stored energy that results from the position or shape of an object is called Potential Energy

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Potential Energy

Stored energy that results from the position or shape of an object is called Potential Energy

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Potential Energy

Work done against conservative force is stored as potential energy

m

m

H

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Potential Energy

Work done against conservative force is stored as potential energy

m

m

H

FE

FS

xm

x=0

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11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Potential Energy

Gravitational Potential Energy

Elastic Potential Energy

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11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Gravitational Potential Energy

Energy that is related to an object’s height with respect to earth's surface is called gravitational potential energy

205 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Gravitational Potential Energy

m

206 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Gravitational Potential Energy

m

m

H

207 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Gravitational Potential Energy

Work done against gravity=WE

m

m

H

m

m

H

208 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Gravitational Potential Energy

Work done against gravity=WE

Stored Potential Energy= V(H)=WE

m

m

H

m

m

H

209 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Gravitational Potential Energy

Work done against gravity=WE

Stored Potential Energy= V(H)=WE

m

m

H

m

m

H

210 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Gravitational Potential Energy

Work done against gravity=WE

Stored Potential Energy= V(H)=WE

m

m

H

m

m

H

211 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Gravitational Potential Energy

Work done against gravity=WE

Stored Potential Energy= V(H)=WE

Potential Energy= (Work done by conservative Force)

m

m

H

m

m

H

212 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Gravitational Potential Energy

Work done against gravity=WE

Stored Potential Energy= V(H)=WE

Potential Energy= (Work done by conservative Force)

m

m

H

m

m

H

213 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Generalised Formula For Potential Energy

(Work done by conservative Force) = Potential Energy

214 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Generalised Formula For Potential Energy

Generalised Formula For Potential Energy

(Work done by conservative Force) = Potential Energy

215 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Elastic Potential Energy

216 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Elastic Potential Energy

217 of 413

11P06.3 Potential Energy and Power

Potential Energy

Potential Energy For a Spring

218 of 413

11P06.3 Potential Energy and Power

Potential Energy

Potential Energy For a Spring

219 of 413

11P06.3 Potential Energy and Power

Potential Energy

Potential Energy For a Spring

220 of 413

11P06.3 Potential Energy and Power

Potential Energy

Potential Energy For a Spring

221 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Potential Energy is always defined relatively,absolute value of PE cannot be calculated.

222 of 413

11P06.3 Potential Energy and Power

Kinetic Energy

Potential Energy

Potential Energy is always defined relatively,absolute value of PE cannot be calculated.

Reference level:The place in a system where the PE is defined to be zero.

examples: A pendulum’s lowest point, Mean Position of spring,Bottom of a mountain etc.

223 of 413

CV-5

Conservation of Energy

224 of 413

11P06.3 Potential Energy and Power

Potential Energy

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy

The Total Mechanical Energy of a System is Conserved if the Forces, Doing Work are Conservative.

225 of 413

11P06.3 Potential Energy and Power

Potential Energy

Conservation of Energy

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy

226 of 413

11P06.3 Potential Energy and Power

Potential Energy

Conservation of Energy

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy

227 of 413

11P06.3 Potential Energy and Power

Potential Energy

Conservation of Energy

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy

228 of 413

11P06.3 Potential Energy and Power

Potential Energy

Conservation of Energy

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy

229 of 413

11P06.3 Potential Energy and Power

Potential Energy

Conservation of Energy

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy

230 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a ball in gravitational field:

231 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a ball in gravitational field:

232 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a ball in gravitational field:

233 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a ball in gravitational field:

234 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a ball in gravitational field:

235 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a ball in gravitational field:

236 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a ball in gravitational field:

237 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a ball in gravitational field:

238 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a Spring:

239 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Conservation of Mechanical Energy for a Pendulum:

240 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

If Non-Conservative Forces are also Applying in system?

241 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Energy

242 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Energy

Energy can neither be created, nor destroyed.Total energy of an isolated system remains constant

243 of 413

ConcepTest

Ready for challenge

244 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: A small roller coaster starts at point A from rest on a curved track as shown in the figure. The friction between the roller coaster and the track is negligible and it always remains in contact with the track. What will be the speed of roller coaster at point D ?

Solution:

θ

245 of 413

Pause the Video

(Time Duration : 2 Minutes)

246 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: A small roller coaster starts at point A from rest on a curved track as shown in the figure. The friction between the roller coaster and the track is negligible and it always remains in contact with the track. What will be the speed of roller coaster at point D ?

Solution:

θ

247 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: A small roller coaster starts at point A from rest on a curved track as shown in the figure. The friction between the roller coaster and the track is negligible and it always remains in contact with the track. What will be the speed of roller coaster at point D ?

Solution:

248 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: A small roller coaster starts at point A from rest on a curved track as shown in the figure. The friction between the roller coaster and the track is negligible and it always remains in contact with the track. What will be the speed of roller coaster at point D ?

Solution:

θ

249 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: A small roller coaster starts at point A from rest on a curved track as shown in the figure. The friction between the roller coaster and the track is negligible and it always remains in contact with the track. What will be the speed of roller coaster at point D ?

Solution:

θ

250 of 413

ConcepTest

Ready for challenge

251 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: What will be the maximum velocity for a block of mass m when it is

stretched xm from its mean position and released from rest ?

Solution:

xm

x=0

252 of 413

Pause the Video

(Time Duration : 2 Minutes)

253 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: What will be the maximum velocity for a block of mass m when it is

stretched xm from its mean position and released from rest ?

Solution:

xm

x=0

254 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: What will be the maximum velocity for a block of mass m when it is

stretched xm from its mean position and released from rest ?

Solution:

xm

x=0

255 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: What will be the maximum velocity for a block of mass m when it is

stretched xm from its mean position and released from rest ?

Solution:

xm

x=0

256 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: What will be the maximum velocity for a block of mass m when it is

stretched xm from its mean position and released from rest ?

Solution:

xm

x=0

257 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: What will be the maximum velocity for a block of mass m when it is

stretched xm from its mean position and released from rest ?

Solution:

xm

x=0

258 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: What will be the maximum velocity for a block of mass m when it is

stretched xm from its mean position and released from rest ?

Solution:

xm

x=0

259 of 413

ConcepTest

Ready for challenge

260 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: A body of mass 5 kg is thrown vertically up with a kinetic energy of 490 J.

At what height the kinetic energy of the body becomes half of the original

value?

Solution:

θ

261 of 413

Pause the Video

(Time Duration : 2 Minutes)

262 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: A body of mass 5 kg is thrown vertically up with a kinetic energy of 490 J.

At what height the kinetic energy of the body becomes half of the original

value?

Solution:

θ

263 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: A body of mass 5 kg is thrown vertically up with a kinetic energy of 490 J.

At what height the kinetic energy of the body becomes half of the original

value?

Solution:

θ

264 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Question: A body of mass 5 kg is thrown vertically up with a kinetic energy of 490 J.

At what height the kinetic energy of the body becomes half of the original

value?

Solution:

θ

265 of 413

CV-6

Vertical Circular Motion

266 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Vertical Circular Motion

Vertical Circular Motion:

267 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Vertical Circular Motion

Vertical Circular Motion:

268 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Vertical Circular Motion

Vertical Circular Motion:

269 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Vertical Circular Motion:

2L

270 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Vertical Circular Motion:

271 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Vertical Circular Motion:

272 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Vertical Circular Motion:

273 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Vertical Circular Motion:

274 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Vertical Circular Motion:

275 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Vertical Circular Motion:

276 of 413

11P06.3 Potential Energy and Power

Conservation of Energy

Conservation of Mechanical Energy

Vertical Circular Motion:

277 of 413

11P06.1 Work

11P06.2 Summary

278 of 413

11P06.1 Work

11P06.2 Summary

279 of 413

PSV 2

280 of 413

θ

Question: A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches the

bottom if the coefficient of friction between the body and the incline is μ.

Solution:

281 of 413

Question: A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches the

bottom if the coefficient of friction between the body and the incline is μ.

Solution:

θ

282 of 413

Question: A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches the

bottom if the coefficient of friction between the body and the incline is μ.

Solution:

θ

283 of 413

θ

Question: A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches the

bottom if the coefficient of friction between the body and the incline is μ.

Solution:

284 of 413

θ

Question: A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches the

bottom if the coefficient of friction between the body and the incline is μ.

Solution:

285 of 413

θ

Question: A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches the

bottom if the coefficient of friction between the body and the incline is μ.

Solution:

286 of 413

θ

Question: A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches the

bottom if the coefficient of friction between the body and the incline is μ.

Solution:

287 of 413

θ

Question: A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches the

bottom if the coefficient of friction between the body and the incline is μ.

Solution:

288 of 413

Question: A body of mass ‘m’ starts from rest and slides down an inclined plane of

height 'h' and angle θ. What is the velocity of the body when it reaches the

bottom if the coefficient of friction between the body and the incline is μ.

Solution:

θ

289 of 413

11P06.3 Potential Energy and Power

11P06.2 Energy

Reference Questions

NCERT : 6.3,6.4,6.18,6.21,6.22,6.25

Work Book : 2,7,11,12,14,18,19

290 of 413

11P06.3

Power and Collision

291 of 413

CV 1

Power

292 of 413

Power

293 of 413

Power

294 of 413

Power

What is Difference in Walking and Running up the stairs?

295 of 413

Power

What is Difference in Walking and Running up the stairs?

In both walking and running up the stairs work done is same The difference between walking and running up these stairs is Power

296 of 413

Power

Power

The rate at which work is done or energy is transformed is called Power

297 of 413

Power

Power

The rate at which work is done or energy is transformed is called Power

298 of 413

Power

Power

The rate at which work is done or energy is transformed is called Power

299 of 413

Power

Power

The rate at which work is done or energy is transformed is called Power

300 of 413

Power

Power

The rate at which work is done or energy is transformed is called Power

301 of 413

Power

Power

Scalar Quantity

Si Unit- Watt

The rate at which work is done or energy is transformed is called Power

302 of 413

Conceptest

Ready for challenge

303 of 413

11P06.3 Potential Energy and Power

Power

Question:An elevator can carry a maximum load of 1800 kg (elevator +passengers)

is moving up with a constant speed of 2 ms–1. The frictional force

Opposing the motion is 4000 N. Determine the minimum power delivered

by the motor to the elevator in watts as well as in horse power.

Solution:

304 of 413

Pause the Video

(Time Duration : 2 Minutes)

305 of 413

11P06.3 Potential Energy and Power

Power

Question:An elevator can carry a maximum load of 1800 kg (elevator +passengers)

is moving up with a constant speed of 2 ms–1. The frictional force

Opposing the motion is 4000 N. Determine the minimum power delivered

by the motor to the elevator in watts as well as in horse power.

Solution:

1800 kg

F

mg

Ff

306 of 413

11P06.3 Potential Energy and Power

Power

Question:An elevator can carry a maximum load of 1800 kg (elevator +passengers)

is moving up with a constant speed of 2 ms–1. The frictional force

Opposing the motion is 4000 N. Determine the minimum power delivered

by the motor to the elevator in watts as well as in horse power.

Solution:

F = mg + Ff

1800 kg

F

mg

Ff

307 of 413

11P06.3 Potential Energy and Power

Power

Question:An elevator can carry a maximum load of 1800 kg (elevator +passengers)

is moving up with a constant speed of 2 ms–1. The frictional force

Opposing the motion is 4000 N. Determine the minimum power delivered

by the motor to the elevator in watts as well as in horse power.

Solution:

F = mg + Ff

= (1800 × 10 ) + 4000

308 of 413

11P06.3 Potential Energy and Power

Power

Question:An elevator can carry a maximum load of 1800 kg (elevator +passengers)

is moving up with a constant speed of 2 ms–1. The frictional force

Opposing the motion is 4000 N. Determine the minimum power delivered

by the motor to the elevator in watts as well as in horse power.

Solution:

F = mg + Ff

= (1800 × 10 ) + 4000

= 22000 N

309 of 413

11P06.3 Potential Energy and Power

Power

Question:An elevator can carry a maximum load of 1800 kg (elevator +passengers)

is moving up with a constant speed of 2 ms–1. The frictional force

Opposing the motion is 4000 N. Determine the minimum power delivered

by the motor to the elevator in watts as well as in horse power.

Solution:

F = mg + Ff

= (1800 × 10 ) + 4000

= 22000 N

Power supplied P = Fv

310 of 413

11P06.3 Potential Energy and Power

Power

Question:An elevator can carry a maximum load of 1800 kg (elevator +passengers)

is moving up with a constant speed of 2 ms–1. The frictional force

Opposing the motion is 4000 N. Determine the minimum power delivered

by the motor to the elevator in watts as well as in horse power.

Solution:

F = mg + Ff

= (1800 × 10 ) + 4000

= 22000 N

Power supplied P = Fv

= 22000 × 2

= 44000 W

311 of 413

11P06.3 Potential Energy and Power

Power

Question:An elevator can carry a maximum load of 1800 kg (elevator +passengers)

is moving up with a constant speed of 2 ms–1. The frictional force

Opposing the motion is 4000 N. Determine the minimum power delivered

by the motor to the elevator in watts as well as in horse power.

Solution:

F = mg + Ff

= (1800 × 10 ) + 4000

= 22000 N

Power supplied P = Fv

= 22000 × 2

= 44000 W

(746 W = 1 hp)

312 of 413

11P06.3 Potential Energy and Power

Power

Question:An elevator can carry a maximum load of 1800 kg (elevator +passengers)

is moving up with a constant speed of 2 ms–1. The frictional force

Opposing the motion is 4000 N. Determine the minimum power delivered

by the motor to the elevator in watts as well as in horse power.

Solution:

F = mg + Ff

= (1800 × 10 ) + 4000

= 22000 N

Power supplied P = Fv

= 22000 × 2

= 44000 W

(746 W = 1 hp)

P =

44000

= 59 hp

746

313 of 413

CV 2

Introduction to Collision

314 of 413

11P06.3 Potential Energy and Power

Collision

Collision

Elastic Collision

315 of 413

11P06.3 Potential Energy and Power

Collision

Completely Inelastic Collision

Collision

Elastic Collision

316 of 413

11P06.3 Potential Energy and Power

Collision

Inelastic Collision

Completely Inelastic Collision

Collision

Elastic Collision

317 of 413

11P06.3 Potential Energy and Power

Collision

Elastic Collision

318 of 413

11P06.3 Potential Energy and Power

Collision

Elastic Collision

319 of 413

11P06.3 Potential Energy and Power

Collision

Elastic Collision

Total Momentum of System is Conserved

Total Kinetic Energy of System Is Conserved

320 of 413

11P06.3 Potential Energy and Power

Collision

Elastic Collision

Total Momentum of System is Conserved

Total Kinetic Energy of System Is Conserved

Deformation due to collision is completely relieved

321 of 413

11P06.3 Potential Energy and Power

Collision

Completely Inelastic Collision

322 of 413

11P06.3 Potential Energy and Power

Collision

Completely Inelastic Collision

323 of 413

11P06.3 Potential Energy and Power

Collision

Completely Inelastic Collision

Total Momentum of System is Conserved

Total Kinetic Energy of System Is Not Conserved

324 of 413

11P06.3 Potential Energy and Power

Collision

Completely Inelastic Collision

Total Momentum of system is conserved

Total Kinetic Energy of system Is not conserved

Deformation due to collision is not relieved

325 of 413

11P06.3 Potential Energy and Power

Collision

Inelastic Collision

326 of 413

11P06.3 Potential Energy and Power

Collision

Inelastic Collision

327 of 413

11P06.3 Potential Energy and Power

Collision

Inelastic Collision

Total Momentum of System is Conserved

Total Kinetic Energy of System Is Not Conserved

328 of 413

11P06.3 Potential Energy and Power

Collision

Inelastic Collision

Total Momentum of System is Conserved

Total Kinetic Energy of System Is Not Conserved

Deformation Due to collision is Partly Relieved

329 of 413

CV 3

Collision in 1-D

330 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Collision in 1-D/Head-on Collision

Before Collision

331 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Collision in 1-D/Head-on Collision

Line of Contact

Before Collision

332 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Collision in 1-D/Head-on Collision

Line of Contact

Before Collision

After Collision

333 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Completely Inelastic Collision

334 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Completely Inelastic Collision

m2

m1

u1

u2

Before Collision

335 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Completely Inelastic Collision

m1

m2

m2

m1

u1

u2

vf

Before Collision

After Collision

336 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Completely Inelastic Collision

m1

m2

m2

m1

u1

u2

vf

Before Collision

After Collision

337 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Completely Inelastic Collision

m1

m2

m2

m1

u1

u2

vf

Before Collision

After Collision

338 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Completely Inelastic Collision

m1

m2

m2

m1

u1

u2

vf

Before Collision

After Collision

339 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Completely Inelastic Collision

m1

m2

m2

m1

u1

vf

Before Collision

After Collision

340 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Completely Inelastic Collision

m1

m2

m2

m1

u1

vf

Before Collision

After Collision

341 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Completely Inelastic Collision

m1

m2

m2

m1

u1

vf

Before Collision

After Collision

342 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

343 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m2

m1

u1

u2

u1>u2

Before Collision

344 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

345 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

346 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

347 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

348 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

349 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

350 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

351 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

352 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

353 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

354 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

355 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

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11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

v2

v1

Before Collision

After Collision

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11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m1

m2

m2

m1

u1

v2

v1

Before Collision

After Collision

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11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m

m

m

m

u1

u1

Before Collision

After Collision

359 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m

m

m

m

u1

u1

Before Collision

After Collision

360 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

361 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m2

m2

u1

Before Collision

After Collision

u1

m1

m1

362 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Elastic Collision

m2

m2

u1

Before Collision

After Collision

u1

m1

m1

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11P06.3 Potential Energy and Power

Collision in 1-D

364 of 413

Conceptest

Ready for challenge

365 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

366 of 413

Pause the Video

(Time Duration : 2 Minutes)

367 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

368 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

369 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

370 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

371 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

372 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

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11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

374 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

375 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:

Solution:

v

2v

376 of 413

Conceptest

Ready for challenge

377 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Question:Two objects, each of mass 1.5 kg, are moving in the same straight line � but in opposite directions. The velocity of each object is 2.5 ms-1

before the collision during which they stick together. What will be the

velocity of the combined object after collision?

Solution:

378 of 413

Pause the Video

(Time Duration : 2 Minutes)

379 of 413

11P06.3 Potential Energy and Power

Collision in 1-D

Question:Two objects, each of mass 1.5 kg, are moving in the same straight line � but in opposite directions. The velocity of each object is 2.5 ms-1

before the collision during which they stick together. What will be the

velocity of the combined object after collision?

Solution:

By Momentum conservation

m1u1+m2u2=(m1+m2)v

380 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 1-D

Question:Two objects, each of mass 1.5 kg, are moving in the same straight line � but in opposite directions. The velocity of each object is 2.5 ms-1

before the collision during which they stick together. What will be the

velocity of the combined object after collision?

Solution:

By Momentum conservation

m1u1+m2u2=(m1+m2)v

1.5✕2.5ㄧ1.5✕2.5=(1.5+1.5)v

381 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 1-D

Question:Two objects, each of mass 1.5 kg, are moving in the same straight line � but in opposite directions. The velocity of each object is 2.5 ms-1

before the collision during which they stick together. What will be the

velocity of the combined object after collision?

Solution:

By Momentum conservation

m1u1+m2u2=(m1+m2)v

1.5✕2.5ㄧ1.5✕2.5=(1.5+1.5)v

0=3v ⇒ v=0

382 of 413

CV 4

Collision in 2-D

383 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

384 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

385 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

386 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

387 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

388 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

389 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

390 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

391 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

392 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

393 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

394 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

u2

395 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

396 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

397 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

398 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

399 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

400 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Collision in 2D / Oblique Collision

When two equal masses undergo a oblique elastic collision with one of them at rest, after the collision, they will move at right angles to each other

401 of 413

Conceptest

Ready for challenge

402 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Question:Body A with speed uA = 50 ms-1 collides elastically with Body B which is

initially stationary After the collision, body A is found to be moving at speed

vA = 25 ms-1 in a direction at 60° to its original direction of motion. Find the

Speed of body B after the collision

(Mass of A = mass of B = 2 kg)

Solution:

403 of 413

Pause the Video

(Time Duration : 2 Minutes)

404 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Question:Body A with speed uA = 50 ms-1 collides elastically with Body B which is

initially stationary After the collision, body A is found to be moving at speed

vA = 25 ms-1 in a direction at 60° to its original direction of motion. Find the

kinetic energy possessed by body B after the collision

(Mass of A = mass of B = 2 kg)

Solution:

A

B

405 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Question:Body A with speed uA = 50 ms-1 collides elastically with Body B which is

initially stationary After the collision, body A is found to be moving at speed

vA = 25 ms-1 in a direction at 60° to its original direction of motion. Find the

kinetic energy possessed by body B after the collision

(Mass of A = mass of B = 2 kg)

Solution:

A

B

406 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Question:Body A with speed uA = 50 ms-1 collides elastically with Body B which is

initially stationary After the collision, body A is found to be moving at speed

vA = 25 ms-1 in a direction at 60° to its original direction of motion. Find the

kinetic energy possessed by body B after the collision

(Mass of A = mass of B = 2 kg)

Solution:

A

B

407 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Question:Body A with speed uA = 50 ms-1 collides elastically with Body B which is

initially stationary After the collision, body A is found to be moving at speed

vA = 25 ms-1 in a direction at 60° to its original direction of motion. Find the

kinetic energy possessed by body B after the collision

(Mass of A = mass of B = 2 kg)

Solution:

A

B

408 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Question:Body A with speed uA = 50 ms-1 collides elastically with Body B which is

initially stationary After the collision, body A is found to be moving at speed

vA = 25 ms-1 in a direction at 60° to its original direction of motion. Find the

kinetic energy possessed by body B after the collision

(Mass of A = mass of B = 2 kg)

Solution:

A

B

409 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

Question:Body A with speed uA = 50 ms-1 collides elastically with Body B which is

initially stationary After the collision, body A is found to be moving at speed

vA = 25 ms-1 in a direction at 60° to its original direction of motion. Find the

kinetic energy possessed by body B after the collision

(Mass of A = mass of B = 2 kg)

Solution:

A

B

410 of 413

11P06.3 Potential Energy and Power

Collision in 2-D

A

B

Question:Body A with speed uA = 50 ms-1 collides elastically with Body B which is

initially stationary After the collision, body A is found to be moving at speed

vA = 25 ms-1 in a direction at 60° to its original direction of motion. Find the

kinetic energy possessed by body B after the collision

(Mass of A = mass of B = 2 kg)

Solution:

ms-1

411 of 413

Summary

Elastic One-Dimensional Collision:

m1

m2

m2

m1

u1

u2

v2

v1

u1>u2

Before Collision

After Collision

412 of 413

Summary

Perfectly Inelastic One Dimensional Collision:

m1

m2

m2

m1

u1

u2

v

u1>u2

Before Collision

After Collision

413 of 413

11P06.3 Potential Energy and Power

11P06.3 Power and Collision

Reference Questions

NCERT : 6.8,6.15,6.16,6.17,6.23,6.24

Work Book : 15,17,20