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Tonia

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## Homework Statement

**https://answers.yahoo.com/question/index?qid=20150607101609AAs8C9t**

Show that momentum is conserved in a reference frame moving at 10.0 m/s in the direction of the moving car.

## Homework Equations

Mass M for 2000 kg car, Mass m for 1500 kg car. To the observer on the ground: mv + 0 = (M + m) v` v` =

**Mv/M + m**

The two cars are one mass after the collision (M + m), with velocity v`:

v` = Mv/M + m

After the collision, M + m is moving at a speed of v` - v

M (V -v) - mv = (M + m) (v` - v)

MV - Mv -mv + Mv + mv = (M + m) v` v` = Mv/(M + m)

## The Attempt at a Solution

[/B]To the observer on the ground: mv + 0 = (M + m) v`

**v` = Mv/M + m**

M (V -v) - mv = (M + m) (v` - v)

MV - Mv -mv + Mv + mv = (M + m) v`

**v` = Mv/(M + m)**

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