physics ch 8

A 1.0-kg block and a 2.0-kg block are pressed together on a horizontal frictionless surface with a compressed very light spring between them. They are not attached to the spring. After they are released and have both moved free of the spring... a))) both blocks will both have the same amount of kinetic energy. b))) both blocks will have equal speeds. c))) the heavier block will have more kinetic energy than the lighter block. d))) the magnitude of the momentum of the heavier block will be greater than the magnitude of the momentum of the lighter block. e))) the lighter block will have more kinetic energy than the heavier block.

e

There must be equal amounts of mass on both side of the center of mass of an object. True or False?

False

In a collision between two objects having unequal masses, how does magnitude of the impulse imparted to the lighter object by the heavier one compare with the magnitude of the impulse imparted to the heavier object by the lighter one? a))) Both objects receive the same impulse. b))) The lighter object receives a larger impulse. c))) The heavier object receives a larger impulse. d))) The answer depends on the ratio of the masses. e))) The answer depends on the ratio of the speeds.

a

In an INELASTIC collision between two objects ___... a))) the kinetic energy of each object is conserved. b))) the momentum of the system is conserved but the kinetic energy of the system is not conserved. c))) the kinetic energy of the system is conserved, but the momentum of the system is not conserved. d))) both the momentum and the kinetic energy of the system are conserved. e))) the momentum of each object is conserved.

b IN an inelastic collision energy is lost as heat etc

A small car has a head-on collision with a large truck. Which of the following statements concerning the magnitude of the average force due to the collision is correct? a))) The small car experiences the greater average force. b))) The small car and the truck experience the same average force. c))) The truck experiences the greater average force. d))) It is impossible to tell since the masses are not given. e)))It is impossible to tell since the velocities are not given.

b The small car and the truck experience the same average force. Newton's Third Law of motions states that: When body A exerts a force on body B, body B exerts an equal force back on body A but in the opposite direction.

On a smooth horizontal floor, an object slides into a spring which is attached to another mass that is initially stationary. When the spring is most compressed, both objects are moving at the same speed. Ignoring friction, what is conserved during this interaction? a))) momentum only b))) momentum and kinetic energy c))) momentum and potential energy d))) kinetic energy only e))) momentum and mechanical energy

e there is no energy loss of any kind and since the forces on the system are internal in nature momentum is conserved