Physics Ch6

A ball with a momentum of +4.0 kg x m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball's momentum?

-8.0 kg x m/s

What type of collision is described when an object at rest collides with AND sticks to another object of the same mass?

An inelastic collision

A large truck collides with a small car. Which undergoes the greater change in momentum?

Both the same

A large truck collides with a small car. Which undergoes the greater force?

Both the same

A large truck collides with a small car. Which undergoes the greater impulse?

Both the same

Which of the following is NOT an example of increasing the time during which momentum changes so that the force of impact is decreased?

Following through when swinging a baseball bat to maximize the force on the ball

What could cause kinetic energy to NOT be conserved?

If the collision was inelastic

In order to decrease the force of impact in a collision, you should:

Increase the time of the collision

. What is true of the total momentum before and after a collision if the collision is inelastic?

It remains constant before and after the collision

. Under what conditions is momentum NOT conserved?

Momentum is conserved in all interactions as long as we include all objects involved in the interaction.

In which type of collision is total kinetic energy conserved?

Only in elastic collisions

In a perfectly inelastic collision, how do the KE before and after the collision compare?

The KE before the collision is greater than after the collision

When comparing the momentum of two moving objects, which of the following is correct?

The less massive object will have less momentum if the velocities are the same.

Why do pole vaulters land in thick crash mats rather than on the ground?

The mats increase the time of collision and so decrease the force

One object collides with another object initially at rest. If the collision is inelastic, what happens to the momentum of the object that was at rest?

The momentum increases

If the velocity of an object is halved, how does its momentum change?

The momentum is halved

A ball is dropped from rest and accelerates toward the ground. In order for momentum to be conserved, what object(s) must be included in the system?

The momentum of the ball and the Earth will be conserved.

If a constant force is applied to an object, which of the following is true?

The more time the force is applied the greater the change in velocity

Which of the following has the greatest momentum?

a tortoise with a mass of 275 kg moving at a velocity of 0.55 m/s

A rubber ball moving at a velocity of +5 m/s hit a flat wall and returned to the thrower at -5 m/s. The momentum of the rubber ball:

decreased and was not conserved.

After colliding, objects are deformed and lose some kinetic energy. Identify the type of collision

inelastic

A roller coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. The momentum of the roller coaster:

is greater down the hill than up the hill.

What are SI units for momentum?

kg x m/s

Which of the following best describes the momentum of two bodies after a two-body collision if the kinetic energy of the system is conserved?

must also be conserved

Two balls of dough collide and stick together. Identify the type of collision

perfectly inelastic

A soccer ball collides with another soccer ball at rest. The total momentum of the balls:

remains constant.

A large truck collides with a small car. Which undergoes the greater change in velocity?

the car

Two objects with different masses collide and bounce back after an elastic collision. Before the collision, the two objects were moving at velocities equal in magnitude but opposite in direction. After the collision,

the less massive object had gained momentum.

In an inelastic collision between two objects with unequal masses,

the momentum of one object will increase by the amount that the momentum of the other object decreases.

The law of conservation of momentum states that:

the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects

A billiard ball collides with a second identical ball in an elastic head-on collision. What is the kinetic energy of the system after the collision compared with the kinetic energy before the collision?

unchanged

Which of the following equations can be used to directly calculate the change in an object's momentum?

𝐹 ∙ ∆t