Module 03 Physics

Two identical freight cars roll without friction towards each other on a level track. One car rolls at 2 m/s and the other car rolls at 1 m/s. After the cars collide, they couple and roll together with a speed of

0.5 m/s.

A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both move with a combined momentum of

1 unit

It takes 40 J to push a large crate 4 m across a floor. The force exerted on the crate is

10 N

What is the mass of a ball moving at 4 m/s with a momentum of 48 kg∙m/s?

12 kg

What is the mass of a ball moving at 3 m/s with a momentum of 48 kg∙m/s?

16 kg

A car moves 4 times as fast as another identical car. Compared with the slower car, the faster car has

16 times the kinetic energy.

When the input piston of a hydraulic press is depressed 20 cm, the output piston is observed to move 1 cm. An input force of 1 N can raise no more than

20 N

A 1000-kg truck moving at 10 m/s that brakes to a stop in 5 s has an average braking force of

2000 N

A hydraulic jack is used to lift an automobile. If the input force is 200 N over a distance of 1 meter, the output force over a distance of 0.1 meter is ideally

2000 N

If you exert 100 J to lift a box in 50 s your power output is

2W

What is the speed of a 4-kg ball with a momentum of 12 kg∙m/s?

3 m/s

A bow is drawn so that it has 40 J of potential energy. When the arrow is fired its kinetic energy is ideally

40 J

A music console is pushed 2 m by a force of 20 N. The work done on the console is

40 J

A 2-kg mass weighs 20 N and is held 4 m above the ground. Its potential energy relative to the ground is

80 J

The impulse-momentum relationship is a direct result of

Newtons second law

An astronaut floating alone in outer space throws a baseball. If the ball moves away at 20 m/s, the astronaut will move in the opposite direction at

a lower speed

When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, the contact time is about 10 times more than for a stiff-legged landing and the average force your body experiences is reduced by

about 10 times

A circus diver drops from a high pole into water far below. When he is half-way down

all of the above

A moving object has

all of the above

Solar power is commonly used to produce

both of these

While driving down the highway a lovebug spatters onto your windshield. Which undergoes the greater impulse?

both the same

A karate chop is more effective if one's hand

bounces upon impact

Whereas impulse involves the time that a force acts, work involves the

distance that a force acts

Which has the greater momentum when moving?

either of these depending on speed

The most underlying feature of machines is

energy conservation

The force that accelerates a rocket in outer space is exerted on the rocket by the

exhaust gases

Which of these forms of energy is NOT renewable?

fossil fuel power

A car that travels twice as fast as another car when braking to a stop will skid

four times as far

A melon is projected into the air with 100 J of kinetic energy in the presence of air resistance. When it returns to its initial level its kinetic energy is

less than 100 J

An object may have potential energy because of its

location

When you can't escape being hit by a fast-moving object, you'll suffer a smaller force if the collision time is

long

Compared with falling on a wooden floor, a wine glass may not break when it falls on a carpeted floor because of

longer time to stop

A heavy truck and a small truck roll down a hill. Neglecting friction, at the bottom of the hill the heavy truck has greater

momentum

A cat and a mouse run along a road with the same kinetic energy. The faster runner is the

mouse

Work is done by gravity on a bowling ball that rolls

on a sloped surface

If you push for an hour against a stationary wall, you do no work

on the wall

A block of ice sliding down an incline has one-quarter its maximum potential energy

one-quarter from the bottom.

The ultimate source of energy from fossil fuels is the

sun

A ball rolling down an incline has its maximum kinetic energy at

the bottom

It is correct to say that impulse is equal to

the change in momentum

No work is done by gravity on a bowling ball that rolls along a bowling alley because

the force on the ball is at right angles to its motion.

A 50-kg sack is lifted 2 m in the same time as a 25-kg sack is lifted 4 m. The power expended in raising the 50-kg sack compared to the power used to lift the 25-kg sack is

the same

After rolling half-way down an incline, a marble's kinetic energy is

the same as its potential energy.

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

the top

The conservation of momentum is most closely related to Newton's

third law

The distinction between impulse and force involves the

time the force acts

If you do work on an object in half the time, your power output is

twice

An object lifted 10 m gains a certain amount of potential energy. If it is lifted 20 m, its gain in potential energy is

twice as much

A 1000-kg car and a 2000-kg car are hoisted the same vertical distance in a service station. Raising the more massive car requires

twice as much work

If you push an object twice as far while applying the same force, you do

twice as much work

When you push an object a certain distance while applying twice the force, you do

twice as much work

Power is defined as the

work done divided by the time to do the work.