Palomar Physics

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 a. force against the cannon is smaller than against the ball b. momentum is mainly concentrated in the cannonball c. cannon has much more mass than the cannonball d. momentum of the cannon is smaller

c. 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 a. half as much b. twice as much c. four times as much d. the same amount

c. four times as much

A block of ice sliding down an incline has half its maximum kinetic energy a. at the top b. at the bottom c. halfway down d. need more information

c. halfway down

A same-size iron ball and wooden ball are dropped simultaneously from a tower and reach the ground at the same time (so ignore air resistance). The iron ball has a greater a. speed b. acceleration c. momentum d. none of the others

c. momentum

An object's weight may properly be expressed in units of a. meters b. kilograms c. newtons d. cubic centimeters

c. newtons

Compared to the weight of a certain object on Earth, the weight of the same object on the moon is a. zero b. larger c. smaller d. impossible to determine

c. smaller

Compared with falling on a stone floor, a wine glass may not break when it falls on a carpeted floor because the a. carpeted floor provides a smaller impulse b. stopping time is shorter on the carpet c. stopping time is longer on the carpet d. carpet provides a smaller impulse and a longer time

c. stopping time is longer on the carpet

If less horizontal force is applied to a sliding object than is needed to maintain a constant velocity (assume there is friction), a. the object accelerates in the direction of the applied force b. the friction force increases c. the object eventually slides to a stop d. None of the other answers

c. the object eventually slides to a stop

If you do work on a skateboard loaded with friends in one-third the usual time, you use a. one third as much power b. the usual power c. three times the usual power d. need more information

c. three times the usual power

If you do work on an object in one-third the usual time, your power output is a. one third the usual power output b. the usual power output c. three times the usual power output d. impossible to predict without additional information

c. 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 a. false b. true only if the car's engine is running c. true d. impossible to know!

c. true

A machine which converts an amount W(in) of work input into an amount W(out) of work output, has an efficiency n. The efficiency of another machine that converts 2W(in) into 4W(out) is a. n b. 3n c. 0 d. 2n e. -4n

d. 2n

A car of mass m, moving with a speed v, has linear momentum p. the momentum of a truck with twice that mass moving with the same speed is a. 0 b. 4p c. 3p d. 2p e. p

d. 2p

The force on a dropped apple hitting the ground depends upon a. the speed of the apple just before it hits b. the time of contact with the ground c. whether or not the apple bounces d. all of the others

d. all of the others

An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much while the force remains constant, its acceleration a. quadruples b. doubles c. stays the same d. halves e. none of these

d. halves

An object has gravitational potential energy due to its a. speed b. acceleration c. momentum d. location e. none of the others

d. location

Compared to the mass of a certain object on Earth, the mass of the same object on the moon is a. one sixth as much b. zero c. six times as much d. the same

d. the same

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 a. twice as much b. four times as much c. sixteen times as much d. unchanged

d. unchanged

Power P is required to do work W in time interval t. What power is required to do work 3W in time interval 5t? a. P b. 3P c. 5P d.5/3 x P e. 3/5 x P

e. 3/5 xP

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 a. 0 b. 4p c. 3p d. 2p e. 6p

e. 6p

A rock is thrown vertically into the air. Neglecting air resistance, at the very top of its trajectory the net force on it is a. less than its weight b. more than its weight c. exactly double than its weight d. exactly half of its weight e. its weight

e. its weight

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 a. kinetic energies b. potential energies c. momentum d. inertias e. none of the others

e. none of the others

Law of conservation of energy

Total energy cannot be created or destroyed

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? a. U b. 2U c. 1/2 U d. 4U e. 1/4 U

a. U

The newton is a unit of a. force b. mass c. density d. inertia

a. force

Padded dashboards in cars are safer in an accident than non-padded ones because passengers hitting the dashboard encounter a. lengthened time of contact b. shorter time of contact c. decreased impulse d. increased momentum

a. lengthened time of contact

Strange as it may seem, it is just as hard to accelerate a car on a level surface on the moon as it is here on the Earth. This is because a. the mass of the car is independent of gravity b. the weight of the car is independent of gravity c. Nonsense! A car is much more easily accelerated on the moon than on the Earth d. It is an unknown phenomenon

a. the mass of the car is independent of gravity

If more horizontal force is applied to a moving object than is needed to maintain a constant velocity (assume there is friction), a. the object accelerates in the direction of the applied force b. the object accelerates opposite the direction of the applied force c. the friction force increases d. None of the other answers

a. the object accelerates in the direction of the applied force

A tiny gun made of a strong but very light material fires a bullet more massive than the gun itself. For such a weapon a. the target would be safer than the shooter b. recoil problems would be lessened c. conservation of momentum would not hold d. both conservation of kinetic energy and momentum would not hold

a. the target would be safer than the shooter

A ball rolling down an incline has its maximum potential energy at a. the top b. a quarter of the way down c. halfway down d. the bottom

a. the top

The force required to maintain an object at a constant velocity in free (frictionless) space is equal to a. zero b. the mass of the object c. the weight of the object d. the force required to stop it e. None of the other answers

a. zero

The impulse-momentum relationship is a direct result of a. Newton's 1st law b. Newton's 2nd law c. Newton's 3rd law d. Newton's law of gravity

b. Newton's 2nd law

It is correct to say that impulse is equal to a. momentum b. a corresponding change in momentum c. force multiplied by the distance it acts d. velocity multiplied by time

b. a corresponding change in momentum

Which of the following has the largest momentum relative to the Earth? a. a tightrope walker crossing Niagara Falls b. a pickup truck speeding along a highway c. a Mack truck parked in a parking lot d. the Science building on campus e. a dog running down the street

b. a pickup truck speeding along a highway

If the mass of an object does not change, a constant net force on the object produces constant a. velocity b. acceleration c. mass d. inertia

b. acceleration

Two identical golf carts move at different speeds. The faster cart has twice the speed and therefore has a. twice the kinetic energy b. four times the kinetic energy c. eight times the kinetic energy d. none of the others

b. four times the kinetic energy

If an object's mass is decreasing while a constant force is applied to the object, the acceleration a. decreases b. increases c. remains the same

b. increases

Whenever the net force on an object is zero, its acceleration a. may be less than zero b. is zero c. may be more than zero

b. is zero

A job is down slowly, while an identical job is done quickly. Both jobs require the same amount of work, but different amounts of a. energy b. power c. effort d. none of the other options

b. power

Your weight is a. equal to your mass b. the gravitational attraction force between you and the Earth. c. a property of mechanical equilibrium d. All of these

b. the gravitational attraction force between you and the Earth

A rock weighs 30 N on Earth. A second rock weighs 30N on the moon. Which of the two rocks has the greater mass? a. the one on earth b. the one on the moon c. they have the same mass d. not enough information to say

b. the one on the moon

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 a. zero b. twice c. four times as much d. unchanged

b. twice

Relative to an initial height, an object raised twice as high has a gravitational potential energy a. half as much b. twice as much c. four times as much d. need more information

b. twice as much

The work you do when pushing a shopping cart twice as far while applying the same force is a. half as much b. twice as much c. four times as much d. the same amount

b. twice as much

The force of friction on a moving object is 10 N. The applied force needed to maintain a constant velocity is a. more than 10 N b. less than 10 N c. 10 N d. 0 N e. impossible to determine

c. 10 N

The brakes of a speeding truck are slammed on and it skids to a stop. If the truck were heavily loaded so that it had twice the total mass, the skidding time would be a. 1/2 as long b. 1 1/2 times as long c. 2 times as long d. 4 times as long e. the same

c. 2 times as long

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 a. 0 b. 4p c. 3p d. 2p e. p

c. 3p

When you jump from 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 your body experiences is a. less than 1/10 as great b. more than 1/10 as great c. about 1/10 as great d. about 10 times as great

c. about 1/10 as great

Hang from a pair of gym rings and the upward support forces of the rings will always a. each be half your weight b. each be equal to your weight c. add up to equal your weight

c. add up to equal your weight

Neglecting friction, a large block of ice and a small block of ice start sliding down an incline together. The heavier block will get to the bottom a. before the light block b. after the light block c. at the same time as the light block

c. at the same as the light block