A 10 g toy car moving to the right at 20 cm/s has a head-on nearly elastic collision with a 24 g toy car moving in the opposite direction at 35 cm/s. After colliding, the 10 g car moves with a velocity of 58 cm/s to the left. Find the speed of the second car after the collision. Answer in units of cm/s.

v' = - 2.5 cm/s

Explanation:

given,

mass of toy car, m = 10 g

speed of right, u = 20 cm/s

mass of toy car, M = 24 g

speed opposite, u' = 35 cm/s

after collision

10 g car moves to left, v = 58 cm/s

v' = ?

using conservation of momentum

m u + M u' = m v + M v'

10 x 20 - 24 x 35 = - 10 x 58 + 24 x v'

24 x v' = - 60

v' = - 2.5 cm/s

speed of second car after collision = - 2.5 cm/s