Exam 8: Momentum and Collisions

Two 0.20-kg balls,moving at 4 m/s east,strike a wall.Ball A bounces backwards at the same speed.Ball B stops.Which statement correctly describes the change in momentum of the two balls?

A 2 000-kg truck traveling at a speed of 6.0 m/s makes a 90 $\degree$ turn in a time of 4.0 s and emerges from this turn with a speed of 4.0 m/s.What is the magnitude of the average resultant force on the truck during this turn?

A 1.0-kg ball is attached to the end of a 2.5-m string to form a pendulum.This pendulum is released from rest with the string horizontal.At the lowest point in its swing when it is moving horizontally,the ball collides elastically with a 2.0-kg block initially at rest on a horizontal frictionless surface.What is the speed of the block just after the collision?

A 3.0-kg mass is released from rest at point A of a circular frictionless track of radius 0.40 m as shown in the figure.The mass slides down the track and collides with a 1.4-kg mass that is initially at rest on a horizontal frictionless surface.If the masses stick together,what is their speed after the collision?