physics 1 quiz

An object at rest near the surface of a distant planet starts to fall freely. If the acceleration there is twice that of the Earth, its speed one second later would be

20 m/s.

A 1000-kg car moving at 10 m/s brakes to a stop in 5 s. The average braking force is

2000 N.

A karate chop delivers a blow of 3000 N to a board that breaks. The force that acts on the hand during this event is

3000 N

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

40 J.

When you stand at rest on a pair of bathroom scales, the readings on the scales will always

add up to equal your weight.

What is the average speed of car B?

0.2 m/s

An object released from rest on another planet requires one second to fall a distance of 6 meters. What is the acceleration in meters per second per second due to gravity on this planet?

12

A car moving at 50 km/hr skids 20 m with locked brakes. How far will the car skid with locked brakes if it were traveling at 150 km/hr?

180 m

Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much

All the above

When properly used, a hydraulic press, like a wheel and axle, is capable of multiplying force input.

Always true

When you relax at rest with your left foot on one bathroom scale and your right foot on a similar scale, each of the scales will

Any of the above may be correct.

Which car(s) accelerate during most of the trip.

Car A

Which car is the furthest from the intersection at time = 0 sec?

Car B

A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, neglecting air drag, its vertical component of velocity

Decreases

The chef at the infamous Fattening Tower of Pizza tosses a spinning disk of uncooked pizza dough into the air. The disk's diameter increases during the flight, while its rotational speed

Decreases

A ball is thrown vertically into the air. Because of air resistance, its speed when it returns to its starting level compared with its initial speed is

Less

Consider a string with several rocks tied along its length at equally spaced intervals. You whirl the string overhead so that the rocks follow circular paths. Compared to a rock in the middle of the string, a rock at the outer end moves

Twice as fast

A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval its acceleration is

Zero

A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is

Zero

According to Newton's law of inertia, a railroad train in motion should continue going forever even if its engine is turned off. We never observe this because railroad trains

always have forces that oppose their motion.

Which has the greater mass

an automobile battery

If no external forces are acting on a moving object, it will

continue moving at the same velocity.

The two measurements necessary for calculating average speed are

distance and time.

Whereas Aristotle relied on logic in explaining nature, Galileo relied on

experiment.

Two identical arrows, one with twice the speed of the other, are fired into a hay bale. The faster arrow will penetrate

four times further than the slower arrow.

If an object is raised twice as high, its potential energy will be

half as much

If an object's mass is decreasing while a constant force is applied to the object, the acceleration

increases.

For an action force, there must be a reaction force that

is exactly equal in magnitude

A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun, straight down towards the water. Neglecting air resistance, the acceleration just before striking the water

is the same for each bullet.

Twelve seconds after starting from rest, an object falling freely will have a speed of

more than 100 m/s.

If a monkey floating in outer space throws his hat away, the hat and the monkey will both

move away from each other, but at different speeds.

An object that has kinetic energy must be

moving.

Horses that move with the fastest linear speed on a merry-go-round are located

near the outside

If you push for a half hour or a whole hour against a stationary wall

no work on the wall is done in either case.

A sandbag is motionless in outer space. A second sandbag with 3 times the mass moving at 12 m/s collides with it. They stick together and move at a speed of

none of these

Which of the following has the largest momentum relative to the Earth's surface?

pickup truck speeding along a highway

A torque acting on an object tends to produce

rotation

Which requires the most amount of work by the brakes of a car?

slowing down from 100 km/h to 70 km/h

It is correct to say that impulse is equal to

the change in momentum it produces

A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that

the milk carton has inertia.

A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that

the milk cartoon has inertia

Which of the following is a scientific hypothesis?

the moon is made of green cheese

After rolling halfway down an incline, a marble's kinetic energy is

the same as its potential energy.

A automobile and a baby carriage traveling at the same speed collide head-on. The impact force is

the same for both.

If you push an object a given distance, while applying twice the force, you do

twice as much work

Two identical gliders slide toward each other on an air track. One moves at 1 m/s and the other at 2 m/s. They collide and stick. The combined mass moves at

1/2 m/s

If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about

10 m/s

An apple falls from a tree and hits the ground 5 meters below. It hits the ground with a speed of about

10 m/s.

An astronaut on another planet drops a 1-kg rock from rest. The astronaut notices that the rock falls 2 meters straight down in one second. On this planet, how much does the rock weigh?

4N

Two people, one twice as massive as the other, attempt a tug-of-war with 12 meters of massless rope on frictionless ice. After a brief time, they meet. The heavier person slides a distance of

4m