multiple choice science questions

a book weighs 4 N. When held at rest in your hands, the net force on the book is _______

0 N

a pencil lies on your desk. If the Earth is moving around the sun at the speed of 30 km/s, how fast is the pencil moving relative to the desk? How fast is the pencil moving relative to the sun?

0 km/s; 30 km/s

A car travels 6 meters in the first second of travel, 6 meters again during the second second of travel, and 6 meters again during the third second. The acceleration is ___

0 m/s

when an object reaches terminal velocity its acceleration is

0 m/s^2

an apple weighs 1 N. the net force on the apple when it is in free fall is

1 N

A ball is thrown straight upward at 10 m/s. Ideally, the ball will return to the thrower's hand with a speed of ________

10 m/s

A freely falling object starts from rest. After falling for one second, it will have the speed of about ______

10 m/s

a girl pulls a 10 kg wagon with a constant force of 20 N. What is the wagons acceleration?

2 m/s^2

a jet has the mass of 40,000 kg. the thrust for each of four engines is 20,000 N. What is the jets acceleration when taking off?

2 m/s^2

a truck exerts a force of 2000 N on a car, accelerating it as 1 m/s. What is the mass of the car?

2000 kg

a person is attracted towards the center of the earth by a 230 N gravitational force. the force with which earth is attracted toward the person is a. very very small b. very very large c. 230 N

230 N

suppose a small plane can fly at 170 km/h relative to the surrounding air. Suppose also that there is a 60 kn/h tailwind. How fast does the plane's shadow move across the ground?

230 km/h

If a rock were equipped with a speedometer and allowed to fall freely on a planet where the acceleration due to gravity is 25 m/s^2, the reading on the speedometer would increase each second by _________

25 m/s

when a woman stands with two feet on a scale reads 280 N. when she lifts one foot, the scale reads ______

280 N

A ball moving at 6 m/s and has a momentum of 24 kg x m/s. what is the balls mass?

4 kg

suppose a car is moving in a straight line and steadily increases its speed. It moves from 35 km/h to 40 km/h the first second and from 40 km/h to 45 km/h the next second. What is the car's acceleration?

5 km/h x s

A 4 kg ball has a momentum of 20 kg x m/s. What is the ball's speed?

5 m/s

a 2 kg ball is thrown at 3 m/s. What is the balls momentum?

6 kg x m/s

A sports car starts from rest and after 5 seconds it is moving at 30 m/s. What is the sport cars acceleration?

6 m/s^2

a man weighing 660 N sits on the floor. He exerts force on the floor of

660 N

an arrow in a bow has 70 J of potential energy. Assuming no loss of energy to heat, how much kinetic energy will it have after it has been shot?

70 J

a sports car has the mass of 1500 kg and accelerates at 5 meters per second squared. What is the magnitude of the force acting on the sports car?

7500 N

how much force is needed to accelerate a 4 kg book to an acceleration of 2 m/s

8 N

suppose you take a trip that covers 640 km and takes 8 hours. What is your average speed?

80 km/h

A cannon with a barrel velocity of 140 m/s launches a cannonball horizontally from a tower. Neglecting air resistance, how far vertically will the cannonball have fallen after 4 seconds?

80 m

An airplane flying into a head wind loses ground speed, and an airplane flying with the wind gains ground speed. If an airplane flies at right angles to the wind, then ground speed is a. more b. less c. unchanged

A. more

At the instant a ball is thrown horizontally with a large force, an identical ball is dropped from the same height. Which ball hits the ground first?

Neither

If you drop a feather and a coin at the same time in a tube filled with air, which will reach the bottom of the tube first?

Neither- they both reach the bottom at the same time

if a girl pushes an object with twice the force for twice the distance she does a. 4 times the work b. the same work c. 8 times the work d. twice the work

a. 4 times the work

which of the following would exert the most pressure on the ground? a. a woman standing in high-heel shoes b. a woman standing in running shoes c. a woman standing on skis

a. a woman standing in high heel shoes

While roller skating granny collides with her tiny grandson who is at rest. ignoring any friction effects the grandsons speed after the collision will be greatest when a. he and granny make a bouncing collision,each going in opposite directions b. granny catches him and they both move together

a. he and granny make a bouncing collision, each going in opposite directions

if your cars runs out of gas, why cant you push on the cars windshield from the inside to move it? a. in order for the car to move, an outside force must be exerted on the car b. a force must be exerted by you on the car's windshield c. a force must be exerted by the exhaust gases on the car a force must be exerted by the car's windshield on you

a. in order for the car to move, an outside force must be exerted on the car

an unfortunate bug splatter against the windshield of a moving car. compared to the deceleration of the car, the deceleration of the bug is a. larger b. the same c. smaller

a. larger

potential energy is the energy an object has because of its a. location b. density c. temperature d. size

a. location

if an object has kinetic energy, then it also must have a. momentum b. impulse c. acceleration d. force

a. momentum

a rocket is able to accelerate in the vacuum of space when it fires its engines. The force that propels the rocket is the force a. of the exhaust gases on the rocket b. of the rocket on the exhaust gases c. neither

a. of the exhaust gases on the rocket

a force is exerted on the tires of a car to accelerate the car along the road. The force is exerted by the a. road b. tires c. air d. engine

a. road

a player hits a ball with a bat. the action force is the impact of the bat against the ball. what is the reaction to this force? a. the force on the ball against the bat b. the weight of the ball c. the grip of the player's hand against the bat d. air resistance on the ball

a. the force on the ball against the bat

which has more momentum, a large truck moving at 30 miles per hour or a small truck moving at 30 miles per hour? a. the large truck b. both have the same c. the small truck

a. the large truck

a table tennis launcher is fired. compared to the force on the ball, the force on the launcher is _______ a. the same b. smaller c. larger

a. the same

suppose a cannon is made of a strong but very light material. suppose also that the cannonball is more massive than the cannon itself. for such a system _______ a. the target would be a safer place than where the operator is located b. the conservation of momentum would not hold c. recoil problems would be lessened d. conservation of energy would not hold

a. the target would be safer place than where the operator is located

compared to a sports car moving at 30 miles per hour, the same sports car is moving at 60 miles per hour has ________ a. twice as much momentum b. the same momentum c. four times as much momentum

a. twice as much momentum

When something falls to the ground, it accelerates. This acceleration is called the acceleration due to gravity and it is symbolized by the letter g. What is the value of g on the Earth's surface?

about 10 m/s^2

in an absence of air resistance, objects fall at constant

acceleration

whenever an object exerts a force on another object, the second objects exerts a force of the same magnitude, but in the opposite direction to that of the first object a. always false b. always true c. sometimes true

b. always true

an archer shoots an arrow. consider the action force to be the bowstring against the arrow. the reaction to this force is a. friction of the ground against the archer's feet b. arrow's push against the bowstring c. weight of the arrow d. air resistance against the bow

b. arrow's push against the bowstring

a cannon recoils from launching a cannonball. the speed if the cannon's recoil is small because the _________ a. impulse on the cannon is less than the impulse on the cannonball b. cannon has far more mass than the cannonball c. momentum of the cannon is unchanged d. force against the cannon is relatively small.

b. cannon had far more mass than the cannonball

you are on a frozen pond and the ice starts to crack. if you lie down on the ice and begin to crawl this will a. increase the total force on the ice b. decrease the pressure on the ice c. increase pressure on the ice d. decrease the total force on the ice

b. decrease the pressure on the ice

accelerations are produced by _______ a. masses b. forces c. velocities d. accelerations

b. forces

a projectile is fired horizontally in a vacuum. The projectile maintains its horizontal component of speed because it a. the net force acting on it is zero b. is not acted on by any horizontal forces c.has no vertical component to begin with d. is not acted on by any forces e. none of the above

b. is not acted on by any horizontal forces

an object that had kinetic energy must have a. acceleration b. momentum c. force applied to maintain it d. none

b. momentum

a job is done slowly, and an identical job is done quickly. Both jobs require the same amount of work but different amounts of a. energy b. power c. both a and b d. none

b. power

suppose you accidentally drive into a tree. which one of the following correctly describes the interaction between your car and the tree? a. the car and tree mutually exert equal forces in the same direction b. the car and the tree mutually exert equal and opposite forces on each other c. the car and tree mutually exert different forces in the same direction d. the car and the tree mutually exert different and opposite forces on each other

b. the car and the tree mutually exert equal and opposite forces on each other

a large truck and a small car traveling at the same speed have a head on collision. The vehicle to undergo to the greater change in velocity will be a. the large truck b. the small car c. neither

b. the small car

The horizontal component of a projectile's velocity is independent of a. the range of the projectile b. the vertical component of its velocity c. time

b. the vertical component of its velocity

suppose the girl is standing on a pond where there is no friction between her feet and the ice. in order to get off the ice, she can a. walk very slowly on tiptoe b. throw something in the direction opposite to the way she wants to go c. bend over touching the ice in front of her and then bring her feet to her hands d. get on her hands and knees and crawl off the ice

b. throw something in the direction opposite to the way she wants to go

if you lift two loads up one story, how much work do you do compared to lifting just one load up one story? a. the same amount b. twice as much c. four times as much d. one half as much

b. twice as much

a karate chop delivers a blow of 2900 N to a board that breaks. The force that acts on the hand during this is a. cannot be determined b. less than 2900 N c. 2900 N d. more than 2900 N

c. 2900 N

suppose you are in a car that is going around a curve. The speedometer reads a constant 30 miles per hour. Which is not true a. your direction is constantly changing b. You and the car are accelerating c. Your velocity is constant d. Your speed is constant

c. Your velocity is constant

energy is changed from one form to another with no net loss or gain a. sometimes true b. always false c. always true

c. always true

earth pulls on the moon, and similarity the moon pulls on earth. this is evidence that the a. earth and moon are simply pulling on each other b. earth and moons pulls comprise an action-reaction pair c. both d. neither

c. both

mechanical energy can be in the form of a. potential energy b. kinetic energy c. both kinetic and potential energy d. neither kinetic or potential energy

c. both kinetic or potential energy

the reason a tennis ball and a solid steel ball will accelerate at the same rate, in the absence of air resistance, is that ______ a. the force acting on them is the same b. they will have the same mass c. the ball with the larger force also has the larger mass d. the ball with the larger force has the smaller mass

c. the ball with the larger force also has the larger mass

a player catches a ball. consider the action force to be the impact of the ball against the player's glove. What is the reaction to this force a. the muscular effort in the player's arms b. friction of the ground against the player's shoes c. the force the glove exerts on the ball d. the player's grip on the glove

c. the force the glove exerts on the ball

After a rock that is thrown straight up reaches the top of its path and is starting to fall back down, its acceleration is ______ a. less than when it was at the top of its path b. greater than when it was at the top of its path c. the same as when it was at the top of its path

c. the same as when it was at the top of its path

a collision is considered elastic if _______ a. the objects don't stick together b. after the collision, the objects have the same shape as before the collision c. there is no lasting deformation d. all of the above

d. all of the above

in order to increase the final momentum of a golf ball, we could ______ a. increase the force acting on it b. increase the time of contact with the ball c. follow through when hitting the ball d. all of the above

d. all of the above

the acceleration produced by a net force on an object is a. in the same direction as the net force b. directly proportional to the magnitude of the net force c. inversely proportional to the mass of the object d. all of the above

d. all of the above

an object at rest much have a. velocity b. speed c. momentum d. energy

d. energy

a moving freight car runs into an identical car at rest on the track. The cars couple together. Compared to the velocity of the first car before the collision, the velocity of the combined cars after the collision is _______ a. more information is needed b. zero c. twice as large d. one half as large

d. one half as large

which has the largest momentum a. tightrope walker b. dog running c. truck parked d. pickup truck traveling

d. pickup truck traveling

as a ball falls, the action force is the pull of earths mass on the ball. What is the reaction to this force? a. nonexistent in this case b. air resistance acting against the ball c. the acceleration of the ball d. the pull of the ball's mass on earth

d. the pull of the ball's mass on earth

in order to catch a ball, a baseball player moves his or her hand backward in the direction of the balls motion. Doing this reduces the force of impact on the players hand principally because _________ a. the time of impact is decreased b. the velocity of the hand is reduced c. the momentum pf the impact is reduced d. the time of impact is increased

d. the time of impact is increased

the amount of potential energy possessed by an elevated object is equal to a. the power used to lift it b. the force needed to lift it c. the distance is lifted d. the work done in lifting it

d. the work done in lifting it

momentum of a system is conserved only when ________ a. there are no forces acting on the system b. there are no internal forces acting on the system c. the system has zero momentum d. there is no net external force acting on the system

d. there is no net external force acting on the system

if you lift one load up two stories, how much work do you do compared to lifting one load up for only one story a. one half as much b. 4 times as much c. one quarter as much d. twice as much

d. twice as much

if a horse pulls on a wagon at rest, the wagon pulls back equally on the horse. can the wagon be set into motion? a. no, because the forces cancel each other b. yes, because the horse's pull on the wagon is larger than the wagons on the horse c. yes, there is a time delay between action and reaction d. yes, because there is a net force acting on the wagon

d. yes, because there is a net force acting on the wagon

as a pendulum swings back and forth a. kinetic energy is transformed into potential energy b. potential energy is transformed into kinetic energy c. all the lowest part of its swing, its energy is all kinetic d.at the end points of its swung, its energy is all potential e. all of the above

e. all of the above

pressure is defined as

force per area

in physics work is

forces x distance

according to Newton's second law, if you gently push on something, it will push ________

gently on you

Which of the following forces acts on a communications satellite in orbit around the earth?

gravity

reason cars have padded dashboards

increase the time of impact in a collision

When you look at the speedometer in a moving car, you can see the car's _____

instantaneous speed

the unit of work is the

joule

A scalar is a quantity that has _______

magnitude

a vector is a quantity that has ______

magnitude and direction

momentum is

mass x velocity

an object that has kinetic energy must be _______

moving

the unit of pressure is _____

newtons per square meter (or pascals)

Jose can jump vertically 1 meter from his skateboard when it is at rest. When the skateboard is moving horizontally, Jose can jump ________

no higher

forces always occur in ______

pairs

what is work done on an object divided by the time taken to do the work

power

Acceleration is

the change in velocity divided by the time interval

A table ball ball launcher is fired. The force of the launcher is _____

the same

an unfortunate bug splatters against the windshield of a moving car. compared to the force of the car on the bug, the force of the bug on the car is

the same

a tennis ball and a solid steel ball with the same diameter are dropped at the same time. which ball has the greater force acting on it

the steel ball

momentum of a system is conserved only when _____

there is no net external force acting on the system

a tennis ball and a solid steel ball with the same diameter are dropped at the same time. which ball has the greater acceleration

they both have the same

the unit of power is the

watt