Two carts collide on a level, friction-less track. Cart A has a mass of 200 g and is initially stationary. Cart B has a mass of 100 g and is initially moving with a velocity of + 2.0 m/s. After the collision between the carts, cart B has a velocity of - 0.5 m/s.

Calculate the velocity of cart A after the collision.

(Use conservation of momentum, KE is not conserved.)

Convert 200 grams and 100 grams to 2kg and 1kg respectively

momentum = mass x velocity

momentum = 1 x 2

initial momentum = 2 kg m/s

second scenario, cart b is moving -.5 m/s

momentum = mass x velocity

momentum = 1 x -.5

final momentum = -.5 kg m/s

momentum has to be the same in both scenarios so the 2 kg truck has to have a momentum of 2.5 kg m/s to push the total momentum of the second scenario to be 2 kg m/s like the first scenario

2.5 = 2 x velocity

velocity of cart a after the collision = 1.25 m/s