A car is moving along a straight line, It moves from O to P in 18 s and returns from P to Q in

6.0 s. What are the average velocity and

average speed of the car in going (a) from O to

P ? and (b) from O to P and back to Q ?

Amoving freight car collides with an identical one that is at rest. if momentum is conserved, what happens to the second car after the collision? it attains the same speed as the first car. it moves at half the speed of the first car. it moves at twice the speed of the first car.