Physics 102 Test 2

When you jump fro an elevated position you usually bend your knees upon reaching the ground, which makes the time of the contact about 10 times that of a stiff legged landing. In this way the average force of your body experiences is:

About 1/10 as great

The force on a dropped apple hitting the ground depends upon:

All of the above (the time of contact with the ground, the speed of the apple just before it hits, whether or not the apple bounces)

A cannon recoils while firing a cannonball. The speed of the cannon's recoil is relatively small (compared to that of the cannonball) because the:

Cannon has much more mass than the cannonball

The work you do when pushing a shopping cart twice as far while applying twice the force is:

Four times as much

Two identical golf carts move at different speeds. The faster cart has twice the speed and therefore has:

Four times the kinetic energy

A block of ice sliding down an incline has half its maximum kinetic energy:

Halfway down

Padded dashboards in cars are safer in an accident than non padded ones because passengers hitting the dashboard encounter:

Lengthened time of contact

An object has gravitational potential energy due to its:

Location

A same size iron ball and wooden ball are dropping simultaneously from a tower and reach the ground at the same time (ignore air resistance). The iron ball has a greater:

Momentum

The impulse-momentum relationship is a direct result of:

Newton's 2nd Law

A light aluminum ball and a heavy lead ball of the same size roll down an incline. When they are halfway down the incline, they will have identical:

None of these (kinetic energies, potential energies, momentum, inertias)

A job is done slowly, while an identical job is done quickly. Both jobs require the same amount of work, but different amounts of:

Power

Compared with falling on a stone floor, a wine glass may not break when it falls on a carpeted floor because the:

Stopping time is longer on the carpet

A tiny gun made of a strong but very light material fires a bullet more massive than the gun itself. For such a weapon:

The target would be safer than the shooter

A ball rolling down an incline has its maximum potential energy at:

The top

If you do work on a skateboard loaded with friends in one third the usual time, you use:

Three times the usual power

If you do work on an object in one third the usual time, your power output is:

Three times the usual power output

Strictly speaking, more fuel is consumed by your car if the air conditioner, headlights, or even a radio is turned on. This statement is:

True

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is:

Twice

Relative to an initial height, an object raised twice as high has gravitational potential energy:

Twice as much

The work you do when pushing a shopping cart twice as far while applying the same force is:

Twice as much

A woman runs up a flight of stairs. The gain in her gravitational potential energy is U. If she runs the same stairs with twice the speed, what is her gain in potential energy?

U

If you find that twice as much work is needed to perform a task but it takes twice as much time, the amount of power required is:

Unchanged

A machine which converts an amount W(in) of work nut to and an amount of W(out) of work output, has an efficiency (n). The efficiency of another machine that converts 2W(in) into 4W(out) is:

2(n)

A car of mass m, moving with a speed of v, has linear momentum p. The momentum of a truck with twice that mass moving with the same speed is:

2p

Power P is required to do work W in time interval t. What power is required to do work 3W in time interval 5t?

3/5 x P

A car of mass m, moving with a speed v, has linear momentum p. The momentum of a car with the same mass moving three times faster is:

3p

A car of mass m, moving with a speed v, has linear momentum p. The momentum of a car with twice that mass moving three times faster is:

6p

It is correct to say that impulse is equal to:

A corresponding change in momentum

Which of the following has the largest momentum relative to the Earth?

A pickup truck speeding along a highway