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Kinetic and Potential Energy

Lesson 28, 29, 30

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  1. energy

the ability to cause motion or change

EX: The ability to do “work”

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How is all energy divided?

All Energy

Potential Energy

Kinetic

Energy

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2. potential energy

the energy stored in a system due to the positions of objects in the system that are interacting at a distance

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Ex: Draw the mountain and the snowboarder (it can be a stick person) at the top and bottom positions

Greater PE

Less PE

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3. kinetic energy

the energy an object has due to its motion

EX:

  • depends on MASS and SPEED (velocity)
  • KE = ½mv2

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A water bottle is knocked off a desk.

When does the bottle have the MOST kinetic energy?

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A. At the top of the fall.

B. In the middle of the fall.

C. At the bottom right before the ground.

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  • C. At the bottom of the fall.

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  • It has the most kinetic energy when its movement and speed are greatest, which is at the bottom of the fall right before it hits the ground.

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  • When an object has the LEAST potential energy is when it has the MOST kinetic energy.

BrainPop-https://www.youtube.com/watch?v=o-V6FrO2kNM

https://www.youtube.com/watch?v=q5YRG7tSSu4

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The faster the object moves, the more kinetic energy is produced.

The greater the mass and speed of an object, the more kinetic energy there will be.

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4. law of conservation of energy

a scientific law that states that the total energy of an isolated system always remains the same

EX:

  • NEVER created or destroyed.
  • Can only be stored or transferred

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5. gravitational potential energy

  • potential energy stored in a system of objects interacting due to gravitational forces
            • Depends on ⚈ Mass

⚈ Distance

Draw a bookcase with the same size books in it.

Less PE

  • Higher =more PE
  • More mass =more PE

More PE

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electric potential energy

potential energy stored in a system of objects interacting by electric forces

EX

EX: More charge means more potential energy

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magnetic potential energy

potential energy stored in a system of objects interacting by magnetic forces

EX:

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How Mass Affects Gravitational Potential Energy

Which color book will have MORE gravitational potential energy?

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Changing an object’s height can change its potential energy.

If I want to drop an apple from the top of one of these three things, where would it have the most potential energy?

A

B

C

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ANSWER

  • The higher the object, the more potential energy!

A

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This is Newton’s Cradle �It demonstrates potential and kinetic energy �Newton's Cradle - Incredible Science

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  • What kind of energy is a coaster gaining in the purple?
    • Potential
  • What kind of energy is a coaster gaining in the red?
    • Kinetic

�Energy and a roller coaster

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Roller Coasters

  • When does the train on this roller coaster have the MOST potential energy?
  • AT THE VERY TOP!

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  • The HIGHER the train is lifted by the motor, the MORE potential energy is produced.

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  • At the top of the hill the train has a huge amount of potential energy, but it has very little kinetic energy.

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  • As the train accelerates down the hill the potential energy is converted into kinetic energy.
  • There is very little

potential energy at the bottom of the hill, but there is a great amount of kinetic energy.

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  • When does the train on this roller coaster have the MOST kinetic energy?

(When is it moving the fastest?)

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  • At the bottom

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7. Mass and Kinetic Energy

Rock with more mass

Rock with less mass

More kinetic energy

Less kinetic energy

Larger splash

Smaller splash

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8. Add red numbers to the graph and the line curving up.

Speed (m/s)

Kinetic Energy (J)

0 1 2 3 4 5 6

5 10 15 20 25 30 35 40

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Stop in 2022 presentation

Types of Potential Energy

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  • elastic potential energy

potential energy resulting from elastic forces; elastic potential energy is a combination of different types of energy

EX: rubber bands, springs

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  • chemical potential energy

potential energy stored in the chemical bonds that hold particles of matter together; chemical potential energy is a combination of different types of energy

EX: Batteries store electric potential energy

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How is all energy divided?

Potential

Energy

Kinetic

Energy

All Energy

Gravitational

Potential

Energy

Elastic

Potential

Energy

Chemical

Potential

Energy

Copy this slide (you can use PE and KE instead of writing the words)

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What is Gravitational Potential Energy?

  • Potential energy due to an object’s position

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  • P.E. = mass x

height x gravity

Don’t look down, Rover!

Good boy!

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What is Elastic Potential Energy?

  • Potential energy due to compression or expansion of an elastic object.

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What is Chemical Potential Energy?

  • Potential energy stored within the chemical bonds of an object

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What is Potential Energy?

  • Stored energy

What is Kinetic Energy?

Which picture is showing KE?�Which picture is showing PE?

  • Energy an object has due to its motion
  • K.E. = .5(mass x speed2)

1

2

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Does the snowboarder have more PE(1) or KE(2) at the top of the hill?

PE(1)

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Does the cart have more PE(1) or KE(2) at the top?

PE(1)

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Joule

The unit for energy

J

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Videos

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  • Mythbusters Newtons