Exam 6: Momentum, Impulse, and Collisions

A 1 200-kg experimental rocket sled on level frictionless rails is loaded with 55.0 kg of propellant.It exhausts the propellant in a 20-s "burn." If the rocket,initially at rest,moves at 155 m/s after the burn,what impulse is experienced by the rocket sled?

Two identical 7-kg bowling balls roll toward each other.The one on the left is moving at +4 m/s while the one on the right is moving at −4 m/s.What is the velocity of each ball after they collide elastically?

A 22.3-g bullet moving at 1 000 m/s is fired through a one-kg block of wood emerging at a speed of 100 m/s.What is the change in the kinetic energy of the bullet-block system as a result of the collision assuming the block is free to move?

A 75-kg man is standing in a 20-kg boat.The man steps to the right thinking he is stepping out onto the dock.However,the following will actually happen (ignore the friction of the water or air on the boat or the man):

Mitch throws a 130-g lump of clay at a 590-g target,which is at rest on a horizontal surface.After impact,the target,including the attached clay,slides 2.8 m before stopping.If the coefficient of friction is μ = 0.50,find the speed of the clay before impact.

A 5.25-g bullet is fired into a 360-g block of wood suspended as a ballistic pendulum.The combined mass swings up to a height of 8.75 cm.What was the magnitude of the momentum of the combined mass immediately after the collision?

A neutron in a nuclear reactor makes an elastic head-on collision with a carbon atom initially at rest.(The mass of the carbon atom is 12 times that of the neutron. )What fraction of the neutron's kinetic energy is transferred to the carbon atom?

Two skaters,both of mass 75.0 kg,are on skates on a frictionless ice pond.One skater throws a 0.40-kg ball at 6.0 m/s to his friend,who catches it and throws it back at 6.0 m/s.When the first skater has caught the returned ball,what is the velocity of each of the two skaters?

In a system with two moving objects,when a collision occurs between the objects:

A 1 000-kg vehicle is moving in the positive y-direction along the y-axis at 10 m/s.A 2 000-kg vehicle is moving in the positive x-direction at along the x-axis at 20 m/s.The vehicles collide and stick together.They move as a single object in a direction θ as measured counterclockwise from the x-axis immediately after the collision.What is the value of tan θ?

A lump of clay is thrown at a wall.A rubber ball of identical mass is thrown with the same speed toward the same wall.Which statement is true?

A 75.0-kg halfback running north with a speed of 11.0 m/s is tackled by a 80.5-kg opponent running south at 7.5 m/s.The collision is perfectly inelastic.Compute the velocity of the two players just after the tackle.