Physics -- FINAL EXAM

What is the acceleration of a car that maintains a constant velocity of 100 km/h for 10 s? --10 m/s2 --0 m/s2 --10 km/h/s --1000 km/h/s

0 m/s2

Two billiard balls having the same mass roll toward each other, each moving at the same speed. What is the combined momentum of the two balls? --10 kg m/s --more information needed to determine --0 kg m/s

0 kg m/s

A 1-kg mass at the Earth's surface weighs about --5 N. --none of these --12 N. --1 N. --10 N.

10 N.

The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is --less than 10 N. --10 N. --more than 10 N.

10 N.

The gain in speed each second for a freely falling object is about --depends on the initial speed --0. --20 m/s. --10 m/s. --5 m/s.

10 m/s.

If you drop an object, it will accelerate downward at a rate of about 10 m/s/s. If you instead throw it downwards, its acceleration (in the absence of air resistance) will be --less than 10 m/s/s. --greater than 10 m/s/s. --10 m/s/s.

10 m/s/s.

A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is about --10. --none of these --greater than 10. --between 0 and 10. --0.

10.

A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is --300 N. --30 N. --3000 N. --more than 3000 N.

3000 N.

An object is pulled northward with a force of 10 N and southward with a force of 15 N. The magnitude of the net force on the object is --none of these --5 N. --15 N. --10 N. --0 N.

5 N.

The impulse-momentum relationship is a direct result of --Newton's third law. --Newton's first law. --Newton's second law.

Newton's second law.

Someone standing at the edge of a cliff throws one ball straight up and another ball straight down at the same initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the greatest speed will be the one initially thrown --They will both hit with the same speed. --upward. --downward.

They will both hit with the same speed.

A Mack truck and a Volkswagen traveling at the same speed have a head-on collision. The vehicle to undergo the greatest change in velocity will be the --Volkswagen. --both the same --Mack truck.

Volkswagen.

A moving object has --energy. --momentum. --velocity. --speed. --all of these

all of these

Which has the greater mass? --automobile battery --king-size pillow --both about the same

automobile battery

When a rifle is fired, it recoils so both the bullet and rifle are set in motion. The rifle and bullet ideally acquire equal --but opposite amounts of momentum. --both of these --amounts of kinetic energy. --none of these

but opposite amounts of momentum.

If an object falls with constant acceleration, the velocity of the object must --be constant also. --none of these --continually decrease. --continually change by the same amount each second. --continually change by varying amounts, depending on its speed.

continually change by the same amount each second.

An object at rest may have --momentum. --speed. --none of these --energy. --velocity.

energy.

A player hits a ball with a bat. The action force is the impact of the bat against the ball. The reaction to this force is the --air resistance on the ball. --none of these --weight of the ball. --force of the ball against the bat. --grip of the player's hand against the ball.

force of the ball against the bat.

A car that travels twice as fast as another when braking to a stop will skid --depends on the mass of the cars --four times as far. --twice as far.

four times as far.

A bullet is fired straight down from the top of a high cliff. Neglecting air resistance, the acceleration of the bullet in meters per second per second is --less than g. --more than g. --g.

g.

When a car is braked to a stop, its kinetic energy is transformed to --heat. --stopping energy. --energy of rest. --potential energy. --energy of motion.

heat.

Two objects of the same size, but unequal weights are dropped from a tall tower. Taking air resistance into consideration, the object to hit the ground first will be the --heavier object. --both hit at the same time. --lighter object. --not enough information

heavier object.

Compared to a recoiling rifle, the bullet fired has a greater --none of these --momentum. --kinetic energy.

kinetic energy.

An object that has potential energy may have this energy because of its --momentum. --location. --acceleration. --none of these --speed.

location.

Compared with falling on a wooden floor, a wine glass may not break when it falls to a carpeted floor because of the --lesser impulse in stopping. --longer time to stop. --both of these --neither of these

longer time to stop.

A kilogram is a measure of an object's --center of mass. --force. --weight. --mass. --gravity.

mass.

If the speed of a moving object doubles, then what else doubles? --all of these --none of these --momentum --acceleration --kinetic energy

momentum

What does an object have when moving that it doesn't have when at rest? --momentum --none of these --inertia --mass --energy

momentum

A moving object on which no forces are acting will continue to move with constant --none of these --acceleration. --impulse. --all of these --momentum.

momentum.

If an object has kinetic energy, then it also must have --none of these --force. --momentum. --impulse. --acceleration.

momentum.

A falling object that has reached its terminal speed continues to gain --neither --both --acceleration. --speed.

neither

A falling object that has reached its terminal speed continues to gain --speed. --neither --both --acceleration.

neither

Compared with a 1-kg block of solid iron, a 2-kg block of solid iron has the same --mass. --none of these --weight. --volume. --all of these

none of these.

While a car travels around a circular track at constant speed, its --none of these --velocity is zero. --acceleration is zero. --both of these

none of these.

If you push for an hour against a stationary wall, you do no work --at all. --none of these --both of these --on the wall.

on the wall.

Your weight is --a property of mechanical equilibrium. --the gravitational attraction between you and the Earth. --the same in all locations. --actually your mass.

the gravitational attraction between you and the Earth.

A light woman and a heavy man jump from an airplane at the same time and open their same-size parachutes at the same time. Which person will get to a state of zero acceleration first? --both should at the same time --not enough information --the heavy man --the light woman

the light woman

A rocket becomes progressively easier to accelerate as it travels upward from the ground mainly because --the applied force on the rocket increases as burning of fuel progresses. --gravity becomes weaker with increased distance. --the mass of the rocket decreases as fuel is burned.

the mass of the rocket decreases as fuel is burned.

Compared with the mass of a certain object on Earth, the mass of the same object on the Moon is --less. --the same. --more.

the same

Suppose a gun were made of a strong but very light material. Suppose also that the pellet is more massive than the gun itself. For such a weapon --conservation of energy would not hold. --recoil problems would be lessened. --both conservation of energy and momentum would not hold. --the target would be safer than the shooter. --conservation of momentum would not hold.

the target would be safer than the shooter.

Two identical arrows, one with twice the kinetic energy of the other, are fired into a hay bale. The faster arrow will penetrate --none of these --twice as far as the slower arrow. --more than four times as far as the slower arrow. --the same distance as the slower arrow. --four times as far as the slower arrow.

twice as far as the slower arrow.

An object is raised above the ground gaining a certain amount of potential energy. If the same object is raised twice as high, it gains --four times as much potential energy. --twice as much potential energy. --neither of these

twice as much potential energy.

If you push an object twice as far while applying the same force, you do --the same amount of work. --four times as much work. --twice as much work.

twice as much work.

One end of a long uniform log is raised to shoulder level. Another identical log is raised at its center to the same level. Raising the second log requires about --twice as much work. --the same amount of work. --more than twice as much work.

twice as much work.

If you do work on an object in half the time, your power output is --half the usual power output. --the same power output. --twice the usual power output.

twice the usual power output.

When a rock thrown straight upwards gets to the exact top of its path, its velocity is --none of these --about 10 m/s and its acceleration is about 10 m/s/s. --zero and its acceleration is about 10 m/s/s. --about 10 m/s and its acceleration is zero. --zero and its acceleration is zero.

zero and its acceleration is about 10 m/s/s.

The force required to maintain an object at a constant velocity in free space is equal to --the weight of the object. --none of these --the force required to stop it. --zero. --the mass of the object.

zero.

When a falling object has reached its terminal velocity, its acceleration is --zero. --g. --constant.

zero.

The scientist to first introduce the concept of inertia was --Galileo. --Aristotle. --Newton. --Copernicus.

Galileo.

When you stand at rest on a pair of bathroom scales, the readings on the scales will always --each be half your weight. --each equal your weight. --add to equal your weight.

add to equal your weight.

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

add up to equal your weight.

A karate expert executes a swift blow and severs a cement block with her bare hand. The magnitude is the same for the --force on both the block and the expert's hand. --all of these --impulse on both the block and the expert's hand. --none of these --time of impact on both the block and the expert's hand.

all of these

An object in mechanical equilibrium is an object --at rest. --all of these --having no acceleration. --moving with constant velocity.

all of these

The resistive force of friction occurs for --all of these. --liquids. --gases. --solids.

all of these.

The two measurements necessary for calculating average speed are --acceleration and time. --distance and time. --velocity and distance. --velocity and time. --distance and acceleration.

distance and time.

Consider drops of water that leak from a dripping faucet. As the drops fall, they --get closer together. --remain at a relatively fixed distance from one another. --get farther apart.

get farther apart.

If a freely falling object were somehow equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be --greater than the second before. --constant. --less and less.

greater than the second before.

One object that has twice as much mass as another object also has twice as much --inertia. --all of these --gravitational acceleration. --volume. --velocity.

inertia.

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 greater for the dropped bullet. --is the same for each bullet. --is greater for the fired bullet. --depends on how high they started. --none of these

is the same for each bullet.

A force is a vector quantity because it has both --action and reaction counterparts. --mass and acceleration. --magnitude and direction.

magnitude and direction.

The maximum acceleration of a car while towing a second car twice its mass, compared to no towing, is --one-third. --none of these --one-half. --one-fourth. --the same.

one-third.

A bullet is dropped from the top of the Empire State Building while another bullet is fired downward from the same location. Neglecting air resistance, acceleration is greatest for the --same for each --dropped bullet. --fired bullet.

same for each

Which requires the most amount of work on the brakes of a car? --slowing down from 70 km/h to a stop. --equal amounts for either. --slowing down from 100 km/h to 70 km/h.

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

The brakes are slammed on a speeding truck and it skids to a stop. If the truck were heavily loaded so it had twice the total mass, the skidding distance would be --4 times as far. --1/2 as far. --1 1/2 times as far. --2 times as far. --the same.

the same.

One-half second after starting from rest, a freely falling object will have a speed of about --none of these --20 m/s. --5 m/s. --2.5 m/s. --10 m/s.

5 m/s.

Action and reaction forces comprise the parts of --a single interaction. --two interactions.

a single interaction.

A truck is moving at constant velocity. Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor --exactly below the midpoint of the ceiling. --ahead of the midpoint of the ceiling. --More information is needed to solve this problem. --behind the midpoint of the ceiling. none of these

exactly below the midpoint of the ceiling.

A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is --the mass of the puck multiplied by 10 m/s/s. --none of these --the weight of the puck divided by the mass of the puck. --0 N. --equal to the weight of the puck.

0 N.

A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is --400 N. --800 N. --none of these --200 N. --1600 N.

400 N.

A math book and a physics book are tied together with a length of string. With the string taut, one book is pushed off the edge of a table. As it falls, the other book is dragged horizontally across the table surface. With no friction, acceleration of the books is --a value that could be greater than g. --g. --zero. --g/2. --a value between zero and g.

a value between zero and g.

Disregarding air resistance, objects fall at constant --distances each successive second. --velocity. --acceleration. --speed.

acceleration.

If the mass of an object does not change, a constant net force on the object produces constant --both of these --none of these --acceleration. --velocity.

acceleration.

Which has zero acceleration? An object --at rest. --all of these --moving at constant velocity. --none of these --in mechanical equilibrium.

all of these

Strictly speaking, if any electrical device in your car is turned on (such as an air conditioner, headlights, or even a radio), more gasoline is burned by the engine. This statement is --true only if the car's engine is stopped. --true only if the car's engine is running. --totally false. --none of these --always true.

always true.

A heavy object and a light object are dropped at the same time from rest in a vacuum. The heavier object reaches the ground --at the same time as the lighter object. --sooner than the lighter object. --later than the lighter object.

at the same time as the lighter object.

The amount of friction that occurs when two material surfaces slide against each other depends on --the "stickiness" of atoms on their surfaces. --none of these --both of these --how much they are pressed together.

both of these

You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum? --both the same --the bug --your car

both the same

When an object falls through the air, its velocity increases and its acceleration --increases. --remains the same whether in air or in vacuum. --decreases.

decreases.

Compared with the force that brings a small car to a stop, the force required to bring a heavy truck traveling at the same speed to a stop --depends on the time involved. --is more. --is less.

depends on the time involved.

In bungee jumping, the change in a jumper's kinetic energy equals the average force of the bungee cord multiplied by the stretching --distance. --none of these --both of these --time.

distance.

The reason a bullet has more kinetic energy than the recoiling rifle from which it is fired is because the force on the bullet acts over a longer --time. --neither of these --both of these --distance.

distance.

An object is propelled along a straight-line path by a force. If the net force were doubled, its acceleration would --stay the same. --halve. --none of these --double. --quadruple.

double.

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 --quadrupled. --unchanged. --doubled. --zero.

doubled.

A heavy truck and a small car rolling down a hill at the same speed are forced to stop in the same amount of time. Compared to the force that stops the car, the force needed to stop the truck is --smaller. --the same. --greater.

greater.

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, its acceleration --halves. --quadruples. --stays the same. --doubles. --none of these

halves.

An object following a straight-line path at constant speed --has zero acceleration. --none of these --has no forces acting on it. --has a net force acting upon it in the direction of motion. --must be moving in a vacuum or in the absence of air drag.

has zero acceleration.

A cannonball shot from a cannon with a long barrel will have a greater muzzle velocity because the cannonball receives a greater --both of these --force. --neither of these --impulse.

impulse.

If a nonrotating object has no acceleration, then we can say for certain that it is --none of these --at rest. --all of these --in mechanical equilibrium. --moving at constant nonzero velocity.

in mechanical equilibrium.

A heavy block at rest is suspended by a vertical rope. When the block is accelerated upward by the rope, the rope tension --remains the same. --decreases. --increases.

increases.

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

increases.

In each second of fall, the distance a freely falling object will fall is --the same, but not 5 m or 10 m. --increasing. --none of these --about 5 m. --about 10 m.

increasing.

A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is --more than its weight. --its weight. --less than its weight.

its weight.

A ball is thrown upwards and caught when it comes back down. In the presence of air resistance, the speed with which it is caught is --more than the speed it had when thrown upwards. --less than the speed it had when thrown upwards. --the same as the speed it had when thrown upwards.

less than the speed it had when thrown upwards.

A force is a vector quantity because it has both --magnitude and direction. --action and reaction counterparts. --mass and acceleration.

magnitude and direction.

A ball is thrown vertically into the air. Because of air resistance, its time coming down compared to its time going up is --more. --the same. --less.

more.

A heavy rock and a light rock in free fall have the same acceleration. The reason the heavy rock doesn't have a greater acceleration is that the --inertia of both rocks is the same. --force due to gravity is the same on each. --ratio of force to mass is the same. --air resistance is always zero in free fall. --none of these

ratio of force to mass is the same.

The force exerted on the tires of a car to directly accelerate it along a road is exerted by the --none of these --road. --air. --engine. --tires.

road.

Two factors that greatly affect air resistance on falling objects are the size and --weight of the object. --mass of the object. --speed of the object.

speed of the object.

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. --there is an action-reaction pair of forces. --gravity tends to hold the milk carton secure. --the milk carton has no acceleration. --none of these

the milk carton has inertia.

Galileo's interpretation of motion differed from Aristotle's in that Galileo emphasized --all of these --time rates. --none of these --the role of distance in describing motion. --the acceleration of free-fall.

time rates.