1. Nov 13, 2007

### jack1234

For the following question the answer is c...but may I know what is the reason?

A car and a large truck travelling at the same speed make a head-on collision and stick together. Which vehicle experiences the larger change in the magnitude of momentum?
(a) the car
(b) the truck
(c) the change in the magnitude of momentum is the same for both
(d） impossible to determine

2. Nov 13, 2007

### Kurdt

Staff Emeritus
In an inelastic collision you'll have an equation of the form $m_1v_1+m_2v_2=(m_1+m_2)v_3$. If you rearrange it a bit you will see:

$$m_1v_1-m_1v_3=m_2v_3-m_2v_2$$

Therefore the magnitudes of the change in momentum are equal.

3. Nov 13, 2007

### jack1234

I see, thanks for the explanation:)

4. Nov 13, 2007