# A ball with a mass of #3 kg# is rolling at #3 m/s# and elastically collides with a resting ball with a mass of #1 kg#. What are the post-collision velocities of the balls?

##### 1 Answer

Jan 2, 2016

#### Answer:

#### Explanation:

As wikipedia suggests:

[Equations' source]

**Derivation**

Conservation of momentum and energy state:

**Momentum**

Since momentum is equal to

**Energy**

Since kinetic energy is equal to

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