Conservation Laws:

The Total Amount of

• Linear Momentum
• Energy
• Angular Momentum

In an Isolated System is Constant

Conservation of linear momentum

• The Law of Conservation of Linear Momentum states:

The total linear momentum of an isolated system is constant.

• Isolated implies no external force:

Conservation of linear momentum, cont’d

• This law helps us deal with collisions.
• If the system’s momentum can not change, the momentum before the collision must equal that after the collision.

Conservation of energy

• The Law of Conservation of Energy: Energy cannot be created or destroyed.
• The total energy of an isolated system is constant.
• Energy can only be transformed from one form to another.

Conservation of charge

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Conservation of energy, cont’d

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Q1. Recoil of gun is based on the principle

(a) Conservation of mass

(b) Conservation of linear momentum

(c) Conservation of angular momentum

(d) Conservation of energy

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Q2. Why does a diver pull his hands and legs close to his body when jumping from a diving board ?

(a) Conservation of mass

(b) Conservation of linear momentum

(c) Conservation of angular momentum

(d) Conservation of energy

END