a car of mass 600 kg is moving at a speed of 20 m/s. it collides with a stationary car of mass 900 kg. if the first car bounces back at 4 m/s,at what speed does the second car move after the collision?

Answer 1

The second car will move at 16 m/s after the collision. This can be calculated using the law of conservation of momentum. The total momentum before the collision is 600 kg x 20 m/s = 12,000 kg m/s. The total momentum after the collision is 600 kg x 4 m/s + 900 kg x v, where v is the velocity of the second car. Therefore, 12,000 = 2400 + 900v, and v = 16 m/s.

Answer 2

12000=2400+900v
v=16m/s