Physics Final Exam
A machine puts out 100 Watts of power for every 1000 Watts put into it. The efficiency of the machine is A) 10%. B) 50%. C) 90%. D) 110%. E) none of these
A) 10%
If a pencil's length and diameter are both multiplied by 10, then its volume is multiplied by A) 10. B) 100. C) 1000. D) 10,000. E) none of these
C) 1000
An airplane that flies at 100 km/h in a 100 km/h hurricane crosswind has a ground speed of A) 0 km/h. B) 100 km/h. C) 141 km/h. D) 200 km/h
C) 141 km/h.
A car moves 4 times as fast as another identical car. Compared to the slower car, the faster car has A) 4 times the KE. B) 8 times the KE. C) 12 times the KE. D) 16 times the KE.
D) 16 times the KE.
A rock suspended by a string weighs 5 N out of water and 3 N when submerged. What is the buoyant force on the rock? A) 8 N B) 5 N C) 3 N D) 2 N E) none of these
D) 2 N
A diver who weighs 500 N steps off a diving board that is 10 m above the water. The diver hits the water with kinetic energy of A) 10 J. B) 500 J. C) 510 J. D) 5000 J. E) more than 5000 J.
D) 5000 J.
If a car accelerates from rest at 2 meters per second per second, its speed 3 seconds later will be about A) 2 m/s. B) 3 m/s. C) 4 m/s. D) 6 m/s
D) 6 m/s
For an action force, there must be a reaction force that A) always acts in the same direction. B) is slightly smaller in magnitude than the action force. C) is slightly larger in amplitude than the action force. D) is exactly equal in magnitude.
D) is exactly equal in magnitude.
A 10-N falling object encounters 10 N of air resistance. The net force on the object is A) 0 N. B) 4 N. C) 6 N. D) 10 N. E) none of these
A) 0 N.
On a balanced seesaw, a boy three times as heavy as his partner sits A) 1/3 the distance from the fulcrum. B) less than 1/3 the distance from the fulcrum. C) more than 1/3 the distance from the fulcrum.
A) 1/3 the distance from the fulcrum
At one instant a heavy object in air is moving upward at 50 meters per second. One second later its speed is approximately A) 40 m/s. B) 50 m/s. C) 55 m/s. D) 60 m/s.
A) 40 m/s.
The mass of a pet turtle that weighs 10 N is A) about 1 kg. B) about 10 kg. C) about 100 kg. D) about 1000 kg. E) none of these
A) about 1 kg.
A pot falls from a ledge and hits the ground 45 m below. The speed with which it hits the ground is (Hint: use the formula for "t", then use the result in the formula for "v") A) about 30 m/s. B) about 60 m/s. C) about 120 m/s. D) more than 120 m/s
A) about 30 m/s.
A skydiver's terminal velocity will be greatest if she falls A) head first. B) lying flat on her back. C) lying flat on her stomach. D) with her parachute open.
A) head first.
If the radius of the Earth somehow decreased with no change in mass, your weight would A) increase. B) not change. C) decrease.
A) increase
When a twirling ice skater brings her arms inward, her rotational speed A) increases. B) decreases. C) remains the same.
A) increases.
If one object has twice as much mass as another object, it also has twice as much A) inertia. B) velocity. C) acceleration due to gravity. D) volume. E) all of these
A) inertia
A lunar month is about 28 days. If the moon were farther from the Earth than it is now, the lunar month would be A) more than 28 days. B) less than 28 days. C) about 28 days. D) difficult to predict without much more information.
A) more than 28 days.
An object that has kinetic energy must be A) moving. B) falling. C) at an elevated position. D) at rest. E) none of these
A) moving.
An industrial flywheel has a greater rotational inertia when most of its mass is A) nearest the rim. B) nearest the axis. C) uniformly spread out as in a disk
A) nearest the rim
What makes an element distinct? A) the number of protons B) the number of neutrons C) the number of electrons D) the total mass of all the particles E) none of these
A) the number of protons
Put a pipe over the end of a wrench when trying to turn a stubborn nut on a bolt, to effectively make the wrench handle twice as long, you'll multiply the torque by A) two. B) four. C) eight.
A) two.
You wish to bolt a sign to a horizontal I-beam supporting a bridge. You will weaken the beam least if you drill the bolt-holes through the A) upper flange. B) lower flange. C) web. D) All these will have the same effect
A) upper flange
A completely submerged object always displaces its own A) volume of fluid. B) weight of fluid. C) density of fluid. D) all of these E) none of these
A) volume of fluid
A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval its acceleration is A) zero. B) 10 km/hr. C) 110 km/hr. D) 1000 km/hr.
A) zero.
What is the buoyant force acting on a 10-ton ship floating in the ocean? A) less than 10 tons B) 10 tons C) more than 10 tons D) depends on density of sea water
B) 10 tons
Do 100 J of work in 50 s and your power output is A) 1/2 W B) 2 W. C) 4 W. D) 50 W. E) 5,000 W.
B) 2 W
If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting position is about A) 1 second. B) 2 seconds. C) 10 seconds. D) 20 seconds. E) not enough information to estimate
B) 2 seconds
An asteroid exerts a 360-N gravitational force on a nearby spacecraft. If the spacecraft moves to a position three times as far from the center of the asteroid, the force will be A) zero. B) 40 N. C) 120 N. D) 360 N. E) 1080 N
B) 40 N
You run horizontally at 8 m/s in a vertically falling rain that falls at 8 m/s. Relative to you, the raindrops are falling at an angle of A) 0°. B) 45°. C) 53°. D) 90°.
B) 45°
A metal block has a mass of 5 grams and a volume of 1 cubic centimeter. A piece of the same kind of metal with a volume of 2 cubic centimeters has a density of A) 2.5 g/cc. B) 5 g/cc. C) 10 g/cc.
B) 5 g/cc
If a gram of antimatter meets a kilogram of matter, the amount of mass to survive is A) 1 gram. B) 999 grams. C) 1 kilogram. D) 1.1 kilogram.
B) 999 grams
Inside a freely falling runaway elevator, your A) acceleration is zero. B) apparent weight is zero. C) gravitational interaction with the Earth is zero. D) all of these E) none of these
B) apparent weight is zero.
A car travels in a circle with constant speed. The net force on the car is A) directed forward, in the direction of travel. B) directed toward the center of the curve. C) zero because the car is not accelerating. D) none of these
B) directed toward the center of the curve.
If the mass of an object were to double while its volume remains the same, its density would A) halve. B) double. C) stay the same. D) become four times as great.
B) 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 A) zero. B) doubled. C) quadrupled. D) unchanged.
B) doubled.
When gas in a container is squeezed to half its volume and the temperature remains the same, the gas pressure A) halves. B) doubles. C) quadruples. D) remains the same.
B) doubles
When gas in a container is squeezed to half its volume, its density A) halves. When gas in a container is squeezed to half its volume, its density A) halves. B) doubles. C) quadruples. D) remains the same. C) quadruples. D) remains the same
B) doubles
If you drop a stone into a hole drilled all the way to the other side of the Earth (neglect the molten core), the stone will A) come to an abrupt stop at the center of the Earth. B) speed up until it gets to the center of the Earth. C) speed up until it reaches the other side of the Earth. D) slow down until it reaches the center
B) speed up until it gets to the center of the Earth
A flywheel's mass is twice that of another of the same size and shape. The more massive flywheel's rotational inertia is A) four times the other's. B) two times the other's. C) the same as the other's. D) half the other's.
B) two times the other's
When a rock thrown straight upwards gets to the exact top of its path, its A) velocity is zero and its acceleration is zero. B) velocity is zero and its acceleration is about 10 meters per second per second. C) velocity is about 10 m/s and its acceleration is zero. D) velocity is about 10 m/s and its acceleration is about 10 meters per second per second. E) none of these
B) velocity is zero and its acceleration is about 10 meters per second per second.
A dam is thicker at the bottom than at the top partly because A) water is denser at deeper levels. B) water pressure is greater with increasing depth. C) surface tension exists only on the surface of liquids. D) it looks better. E) none of these
B) water pressure is greater with increasing depth
A 1-kg glider and a 2-kg glider both slide toward each other at 1 m/s on an air track. They collide and stick. The combined mass moves at A) 0 m/s. B) 1/2 m/s. C) 1/3 m/s. D) 1/6 m/s. E) 1.5 m/s.
C) 1/3 m/s.
A 5-kg shark swimming at a speed of 1 m/s swallows an absent-minded 1-kg fish swimming toward it at 4 m/s. The speed of the shark after this meal is A) 1/2 m/s. B) 1/5 m/s. C) 1/6 m/s. D) 2/3 m/s. E) 3/2 m/s.
C) 1/6 m/s.
The force of friction on a sliding 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.
C) 10 N.
About how high can water be theoretically lifted by a vacuum pump at sea level? A) less than 10.3 m B) more than 10.3 m C) 10.3 m
C) 10.3 m
A wooden block has a mass of 1000 kg and a volume of 2 cubic meters. What is the block's density? A) 100 kg per cubic meter B) 200 kg per cubic meter C) 500 kg per cubic meter D) 1000 kg per cubic meter E) none of these
C) 500 kg per cubic meter
Which has the greater density, a lake full of water or a cup full of lake water? A) the cup full of lake water B) the lake full of lake water C) Both have the same density. D) It is impossible to tell without knowing the size of the lake.
C) Both have the same density
A ring, a disk, and a solid sphere begin rolling down a hill together. The one to reach the bottom first is the Iring = 1mr^2 Idisk = 1/2mr^2 . I sphere = 2/5m^r2 A) ring. B) disk. C) sphere. D) They all reach the bottom at the same time. E) Not enough information is given.
C) Sphere
A block of wood weighing 5 N in air, is difficult to fully submerge in a pool of mercury because the buoyant force when fully submerged is A) less than 5 N. B) 5 N. C) much more than 5 N
C) much more than 5 N
You are paddling a canoe at a speed of 8 km/h directly across a river that flows at 6 km/h, as shown in the figure. What is the resultant speed relative to the shore? A) 196 km/h B) 4 km/h C) 100 km/h D) 10 km/h
D) 10 km/h
A ball is moving at 3 m/s and has a momentum of 48 kg m/s. What is the ball's mass? A) 4 kg B) 12 kg C) 16 kg D) 144 kg E) none of these
D) 144 kg
An atomic mass unit (amu) is 1/12 the mass of A) an electron. B) a proton. C) a hydrogen atom. D) a carbon atom. E) a uranium atom
D) a carbon atom
An object in mechanical equilibrium is an object A) at rest. B) moving with constant velocity. C) having no acceleration. D) all of these
D) all of these
Our moon travels the fastest as it orbits the Earth when it is A) performing an eclipse. B) rotating. C) revolving. D) closest. E) All of the above choices are true.
D) closest
When the distance between two stars decreases by half, the force between them A) decreases by one-quarter. B) decreases by one-half. C) increases to twice as much. D) increases to four times as much. E) stays the same.
D) increases to four times as much.
An object may have potential energy because of its A) speed. B) acceleration. C) momentum. D) location. E) none of these
D) location.
A bullet is fired horizontally with an initial velocity of 300 m/s from a tower 20 m high. If air resistance is negligible, the horizontal distance the bullet travels before hitting the ground is about A) 200 m. B) 300 m. C) 400 m. D) 500 m. E) 600 m.
E) 600 m.
An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the A) combined weight of the arrow and bowstring. B) air resistance against the bow. C) friction of the ground against the archer's feet. D) grip of the archer's hand on the bow. E) arrow's push against the bowstring.
E) arrow's push against the bowstring.
Ice cubes submerged at the bottom of a liquid indicate that the liquid A) produces no buoyant force on the ice. B) has dissolved air. C) is warmer than the ice. D) is not displaced by the submerged ice. E) is less dense than ice
E) is less dense than ice
Half way to the center of a completely hollow planet with a thin uniform shell, your weight would be A) one-quarter of your weight on the surface. B) one-half of your weight on the surface. C) three-quarters of your weight on the surface. D) the same as at the surface. E) zero
E) zero
Two projectiles are fired from ground level at equal speeds but different angles. One is fired at an angle of 30 degrees and the other at 60 degrees. The projectile to hit the ground first will be the one fired at (neglect air resistance) A) 30 degrees. B) 60 degrees. C) Both hit at the same time
A) 30 degrees.
The weight of matter comes mostly from its A) protons. B) electrons. C) neutrons
A) protons.
When a load is placed on the middle of a horizontal beam supported at each end, the bottom part of the beam undergoes A) tension. B) compression.
A) tension
Which is most responsible for the ocean tides? A) the moon B) the sun C) Both contribute equally
A) the moon
Consider two mercury barometers, one with twice the cross-sectional area of the other. Neglecting capillarity, mercury in the smaller tube will rise A) the same height as in the larger tube. B) twice as high as mercury in the larger tube. C) four times as high as mercury in the larger tube. D) more than four times as high as in the larger tube. E) none of these
A) the same height as in the larger tube
The ratio of output force to input force of a hydraulic press will be equal to the ratio of the output and input piston A) diameters. B) areas. C) radii. D) all of these E) none of these
B) areas
When weight is applied to the top of a stone arch, all of the stone blocks in the arch undergo A) tension. B) compression. C) expansion. D) change of phase
B) compression
If no external forces (F = 0) are acting on a moving object, it will A) continue moving at the same speed. B) continue moving at the same velocity. C) move slower and slower until it finally stops.
B) continue moving at the same velocity.
If the Earth's mass decreased to one-half its original mass with no change in radius, then your weight would A) decrease to one quarter your original weight. B) decrease to one half your original weight. C) stay the same. D) none of these
B) decrease to one half your original weight.
A skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration A) increases. B) decreases. C) remains unchanged regardless of air resistance.
B) decreases.
The chemical properties of matter come mostly from its A) protons. B) electrons. C) neutrons.
B) electrons.
The volume of matter comes mostly from its A) protons. B) electrons. C) neutrons
B) electrons.
The force of gravity does work on a satellite when it is in A) circular orbit. B) elliptical orbit. C) both of these D) neither of these
B) elliptical orbit.
A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the A) player's grip on the glove. B) force the glove exerts on the ball. C) friction of the ground against the player's shoes. D) muscular effort in the player's arms. E) none of these
B) force the glove exerts on the ball
An object following a straight-line path at constant speed A) has a net force acting upon it in the direction of motion. B) has zero acceleration. C) has no forces acting on it. D) none of these
B) has zero acceleration
When a boat sails from fresh water to salt water, the boat will float A) lower in the water. B) higher in the water. C) at the same water level.
B) higher in the water.
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.
Two tennis balls fall through the air from a tall building. One of them is filled with lead pellets. The ball to reach the ground first is the A) regular ball. B) lead-filled ball. C) same for both
B) lead-filled ball.
Acceleration is greater for a satellite when it is at the A) apogee. B) perigee. C) zenith. D) same acceleration at all of the above places.
B) perigee
To multiply the input force of a hydraulic lift , the input end should be the one having the A) larger diameter piston. B) smaller diameter piston. C) Relative piston sizes don't matter
B) smaller diameter piston.
It is correct to say that impulse is equal to A) momentum. B) the change in momentum it produces. C) the force multiplied by the distance the force acts. D) velocity multiplied by time.
B) the change in momentum it produces.
A hydraulic press multiplies a force by 100. This multiplication is done at the expense of A) energy, which is divided by 100. B) the distance through which the force acts. C) the time through which the force acts, which is multiplied by 100. D) the mechanism providing the force. E) none of these
B) the distance through which the force acts
A weightless spring is stretched 10 cm by a suspended 1-kg block. If two such springs are used to suspend the block, one spring above the other, to effectively provide one double-length spring, then the total stretch of the double-length spring will be A) 5 cm. B) 10 cm. C) 20 cm. D) 30 cm. E) none of these
C) 20 cm
A 5000-kg freight car runs into a 10,000-kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. What was the initial speed of the 5000-kg car? A) 4 m/s B) 5 m/s C) 6 m/s D) 8 m/s E) none of these
C) 6 m/s
Suppose you're on a Ferris wheel at a carnival, seated 10 m from the Ferris wheel's axis. If you make a complete rotation each minute, your linear speed is A) 10 m/min. B) 31.4 m/min. C) 62.8 m/min. D) 100 m/min. E) Not enough information is given.
C) 62.8 m/min
Tripling the linear size of an object multiplies its area by A) 3 and its volume by 9. B) 9 and its volume by 18. C) 9 and its volume by 27. D) 27 and its volume by 81. E) none of these
C) 9 and its volume by 27
If an object of constant mass experiences a constant net force, it will have a constant A) velocity. B) speed. C) acceleration. D) position. E) more than one of the above
C) acceleration.
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 equal your weight. C) add up to equal your weight.
C) add up to equal your weight.
In an electrically neutral atom, the number of protons in the nucleus is balanced by an equal number of A) neutrons. B) quarks. C) orbital electrons. D) all of these E) none of these
C) orbital electrons.
When a star collapses to form a black hole, its mass A) increases. B) decreases. C) remains the same.
C) remains the same
When an ice cube in a glass of water melts, the water level A) rises. B) falls. C) remains the same.
C) remains the same
A projectile is fired vertically from the surface of the Earth at 5 km/s. The projectile will A) go into circular about the Earth. B) go into an elliptical orbit about the Earth. C) rise and fall back to the Earth's surface. D) none of these
C) rise and fall back to the Earth's surface.
A car traveling at 100 km/hr strikes an unfortunate bug and splatters it. The force of impact is A) greater on the bug. B) greater on the car. C) the same for both.
C) the same for both.
To catch a ball, a baseball player extends the hand forward before impact with the ball and then lets it ride backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because the A) force of impact is reduced. B) relative velocity is less. C) time of impact is increased. D) time of impact is decreased. E) none of these
C) time of impact is increased.
A 1000-kg car and a 2000-kg car are hoisted the same distance. Raising the more massive car requires A) less work. B) as much work. C) twice as much work. D) four times as much work. E) more than four times as much work.
C) twice as much work.
An object lifted 10 meters gains 200 J of potential energy. If the same object is lifted 20 meters, its potential energy gain is A) half as much. B) the same. C) twice as much. D) four times as much. E) more than four times as much.
C) twice as much.
A skydiver steps from a helicopter and falls for a few seconds until he reaches his terminal velocity. Thereafter, until he opens his parachute, his acceleration A) is constant. B) increases. C) decreases. D) is zero. E) none of these
D) is zero
The reason that buoyant force acts upward on a submerged object is that A) it acts in a direction to oppose gravity. B) if it acted downward, nothing would float. C) the weight of fluid displaced reacts with an upward force. D) upward pressure against the bottom is greater than downward pressure against the top of the submerged object.
D) upward pressure against the bottom is greater than downward pressure against the top of the submerged object
Compared to the energy it takes to separate oxygen and hydrogen from water, the amount of energy given off when they recombine is A) slightly more. B) slightly less. C) much more. D) much less. E) the same
E) the same.