Momentum Bonus Problems
1. ) A glass ball of mass 5.0 g moves at a velocity of 20.0 m/s. The ball collides with a second glass ball of mass 10.0 g, which is moving along the same line with a velocity of 10.0 m/s. After the collision, the 5.0-ball is still moving with a velocity of 8.0 m/s. a.) What is the change of momentum of the 5.0-g ball? b.) What is the change of momentum of the 10 g ball?
2.) A 92 kg fullback running at 5.0 m/s is diving for a touchdown. Just as he reaches the goal line, he is met head-on in midair by two 75 kg linebackers, one moving at 2 m/s and the other at 4 m/s. If upon collision they become entangled as one mass, with what velocity do they travel? Does the fullback score?
3.) A 845-kg drag race car accelerates from rest to 100 km/h in .9 seconds. a.) What is the change in momentum of the car? b.) What average force (and direction) is exerted on the car?
4.) A car moving at 36 km/h (10 m/s) crashes into a barrier and stops in .25 m. a.) Find the time required to stop the car. b.) If a 40-kg child is to be stopped in the same time as the car, what average force must be exerted?
5.) Before a collision a 25 kg mass is moving at 12 m/s. Find the impulse that acted on this mass if after the collision: a.) the mass moves at 8 m/s. b.) the mass moves at -8 m/s.
6.) Each croquet ball in a set has a mass of .5 kg. The green ball, traveling at 12 m/s, strikes the blue ball, which is at rest. Assuming that all collisions are head-on, find the final speed of the blue ball in each of the following situations: a.) The green ball stops moving after it strikes the blue ball. b.) The green ball continues moving after the collision at 2.4 m/s in the same direction. c.) The green ball continues moving after the collision at .3 m/s in the same direction. d.) the blue ball and the green ball move in the same direction after the collision; the green ball has a speed of 1.6 m/s.
7.) A 56 kg ice skater traveling at 4 m/s to the north suddenly grabs the hand of a 65 kg skater traveling at 12 m/s in the opposite direction as they pass. The two skaters continue skating together with joined hands. a.) What is the final velocity of the two skaters?
8.) A 2250 kg car traveling at 10 m/s collides with a 2750 kg car that is initially at rest at a stoplight. The cars stick together and move 2.5m before friction causes them to stop. Determine the coefficient of kinetic friction between the cars and the road, assuming that the negative acceleration is constant and that all wheels on both carslock at thetime of impact.
9.) A 3 kg mud ball has a perfectly inelastic collision with a second ball that is initially at rest. The composite system moves with a speed equal to one-third the original speed of the 3 kg mud ball. What is the mass of the second mud ball?
10.) If a .150 kg baseball has a momentum of 6.90 kg*m/s as it is thrown from home to second base, what is its velocity?
11.) A .025 kg golf ball moving at 18 m/s crashes through the window of a house in 5 *10-4 s. After the crash, the ball continues in the same direction with a speed of 10 m/s. Assuming the force exerted on the ball by the window was constant, what was the magnitude of this force ?
12.) A 1550 kg car moving south at 10 m/s collides witha 2550 kg car moving north. The cars stick together and move as a unit after the collision at a velocity of 5.22 m/s to the north. Find the velocity of the 2550 kg car before the collision.