A small, 200g cart is moving at 1.20m/s on an air track when it collides with a larger, 3.00kg cart at rest. After the collision, the small cart recoils at 0.820m/s .
What is the speed of the large cart after the collision?

Question

A small, 200g cart is moving at 1.20m/s on an air track when it collides with a larger, 3.00kg cart at rest. After the collision, the small cart recoils at 0.820m/s .
What is the speed of the large cart after the collision?

matt101 · Answer

Use conservation of momentum. Say m and M are the masses of the two carts and v and V are the corresponding speeds:

$$m_1v_1+M_1V_1=m_2v_2+M_2V_2$$
You should be able to figure out what you need using this equation!

shamim · Answer

Use 
m1u1+m2u2=m1v1+m2v2