Physics 131 Final Exam

Nellie pulls on a 10 kg wagon with a constant horizontal force of 30 N. If there are no other horizontal forces, what is the wagon's acceleration a. 3 m/s^2 b. 10 m/s^2 c. 30 m/s^2 d. 300 m/s^2 e. 0.3 m/s^2

a

Newtons law of cooling applies to objects that are a. both of these b. heating c. cooling d. none of these

a

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

a

Thanks to new NCAA regulations, all of the players on our Men's basketball team will be given a 2015 Bentley. During a test drive one of the players splattered a bug on his windshield while traveling 55 mph. Which experienced the greater force? a. The same for both. b. The car. c. more information needed d. The bug.

a

The chef at the infamous Fattening Tower of Pizza tosses a spinning disk of uncooked pizza dough into the air. The disk becomes wider during its flight, while its rotational speed a. slows b. quickens c. remains constant

a

The famous Leaning Tower of Pisa doesn't topple over because its center of gravity is a. above a place of support. b. in the same place as its center of mass. c. stabilized by its structure. d. relatively low for such a tall building. e. displaced from its center.

a

The faster a fluid moves, the a. less its internal pressure b. greater its internal pressure c. internal pressure is unaffected

a

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

a

The planet Earth loses heat mainly by a. radiation b. all of these c. conduction d. convection

a

The time it takes a projectile fired straight up at 10m/s to reach the top of its path is about a. 1s b. 2s c. 10s d. not enough info

a

The white hot sparks that strike your skin from a 4th of july type sparkler don't harm you because a. the energy per molecule is high, but little energy is transferred because of the few molecules in the spark b. they have a low temperature c. the energy per molecule is very low

a

Water pressure is greatest against the a. bottom of a submerged object b. none of these c. is the same against all surfaces d. sides of a submerged object e. top of a submerged object

a

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. more than four times as much. b. four times as much. c. twice as much. d. half as much. e. the same.

c

Compared to the volume of a kg of feathers, the volume of a kg of lead is a. the same b. more c. less

c

If a stone falls to the bottom of a mineshaft in 6 seconds, then the depth of the shaft is about a. 60m b. more than 200 m c. 180 m d. 120 m

c

If you place a pipe over the end of a wrench when trying to rotate a stubborn bolt, effectively making the wrench handle twice as long, you'll multiply the torque by a. either b. four c. two

c

Joshua is attracted to earth by a 500 N gravitational force. The Earth is attracted toward Joshua with a force of a. 0 b. 250 N c. 500 N d. 1000 N

c

Two people are balanced on a see-saw. If one person leans toward the center of the see-saw, that persons end of the see-saw will a. rise and then fall b. stay at the same level c. fall and then rise d. rise e. fall

d

What is the acceleration of a car that starts from rest and 5 seconds later reaches a speed of 20 m/s? a. 1 m/s b. 2 m/s c. 3 m/s d. 4 m/s e. 5 m/s

d

What is the buoyant force acting on a 10 ton ship floating in the ocean? a. depends on density of sea water b. more than 10 tons c. less than 10 tons d. 10 tons

d

What is the weight of water displaced by a 100 ton floating ship a 100 cubic meters b. less than 100 tons c. more than 100 tons d. 100 tons e. depends on the ships shape

d

When a bimetallic bar made of copper and iron strips is heated, the bar bends toward the iron strip. The reason for this is a. iron expands more than copper b. copper gets hotter before iron c. iron gets hotter before copper d. copper expands more than iron e. none of these

d

Which of the following is absolute and can never be questioned? a. theory b. hypothesis c. keith d. nonsense, they can all be proven wrong e. law

d

A 2-kg mass is held 4 m above the ground. What is the approximate potential energy of the mass with respect to the ground? a. 6J b. 32J c. none of these d. 8J e. 80J

e

A 5 kg shark swimming at a speed of 1 m/s swallows an absent minded 1 kg fish swimming toward it at 5 m/s. The speed of the shark after this meal is a. 0 b. 1/2 m/s c. 1/5 m/s d. 1/6 m/s e. 5.3 m/s

a

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

a

A cannon recoils while firing a cannonball. The speed of the cannon's recoil is relatively small because the a. cannon has much more mass than the cannonball b. momentum is mainly concentrated in the cannonball c. force against the cannon is smaller than against the ball d. momentum of the cannon is smaller

a

A car moves 4 times as fast as another identical car. Compared to the slower car, the faster car has a. 16 times the KE. b. 12 times the KE. c. 8 times the KE. d. 4 times the KE.

a

A car traveling at 100 km/h strikes an unfortunate bug and splatters it. the force of impact is a. the same for both b. greater on the bug c. greater on the car

a

A car travels in a circle with constant speed. The net force on the car is a. directed towards the center of the curve b. directed forward, in the direction of travel c. none of these d. zero, because the car is not accelerating

a

A car with closed windows makes a left hand turn. A helium filled balloon in the car will a. move to the left b. move to the back c. move to the right d. not move e. move to the front

a

Atmospheric pressure is caused by the a. weight of the atmosphere b. density of the atmosphere c. effect of the suns every on the atmosphere d. temperature of the atmosphere

a

Both black and white road surfaces absorb sunlight. At the end of the sunny day the warmer road surface will be a. the black surface b. the white surface c neither, there is no difference

a

For the astronauts outside the orbiting space shuttle, there is no force of Earths gravity acting on them. This statement is a. always false b. always true while in orbit c. sometimes true while in orbit

a

Horses with the greatest linear speed on a merry go round are located a. near the outside b. anywhere, because they all move at the same speed c. near the center

a

When you stand at rest with your left foot on one bathroom scale and your right foot on a similar scale, each of the scales will a. show readings that when added equal your weight b. cancel your weight c. read half your weight d. read your weight

a

When you touch a cold piece of ice with your finger, the energy flows a. from your finger to the ice b. from the ice to your finger c. actually, both ways

a

Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to a. follow a straight line path b. slow down c. follow a circular path. d. stop

a

A 500 N parachutist opens his chute and experiences an air resistance force of 800 N. the net force on the parachutist is then a. 500 N upward b. 300 N upward c. 500 N downward d. 300 N downward e. 800 N downward

b

A black hole a. an empty region of space with a huge gravitational field b. simply the remains of a giant star that has undergone gravitational collapse c. a small region that contains the mass of many galaxies

b

A bullet fired horizontally over level ground hits the gourd in 0.5 second. If it had been fired with twice the speed in the same direction, It would have hit the ground in a. less than 0.5 s b. 0.5s c. more than 0.5 s

b

A bullet is dropped into a river from a very high bridge at the same time as another bullet is fired straight downward from a rifle. Neglecting air resistance, the acceleration just before striking the water is a. greater for the dropped bullet b. the same for each bullet c. greater for the fired bullet d. none of the above

b

A car moving at 50 km/hr skids 20 m with locked breaks. How far will the car skid with locked breaks if it were traveling at 150 km/hr? a. 60 m b. 180 m c. 20 m d. 120 m e. 90 m

b

A coconut and a bird's feather fall from a tree through the air to the ground below. The force of air resistance is a. the same on each b. greater on the coconut c. greater on the feather

b

A man leans over the edge of a cliff and throws a rock upward at 5 m/s. How far below the level from which it was thrown is the rock 2 s later a. 20 m b. 10 m c. 15 m d. 5 m

b

A ring and a disk both at rest roll down a hill together. Which accelerates slower? a. both roll at the same speed b. ring c. depends on the masses d. disk e. need more information

b

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

b

An educated scientific guess is a. theory b. hypothesis c. either of these d. neither of these

b

Facts in the field of science a. are absolute b. are changeable c. are more important than theories d. mean very little

b

For a scientific hypothesis to be valid, there must be a test for proving it a. right b. wrong c. conclusively one way or the other

b

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. 10 seconds. b. 2 seconds. c. 1 second. d. not enough information to estimate e. 20 seconds.

b

If the mass of the Earth somehow increased with no change in radius, your weight would a. stay the same b. increase also c. decrease

b

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

b

Since each rolling wheel of a railroad train is tapered, the narrow part of the wheel has a tangential speed that is a. the same as that of the wide part b. smaller than that of the wide part c. greater than that of the wide part

b

Suppose you are standing on a weighing scale and all of a sudden the atmosphere vanished. The reading on the scale would a. decrease b. increase c. quickly reduce to 0 d. remain the same

b

The fastest moving planet in a solar system is a. the smallest planet b. the planet nearest the sun c. the most massive planet d. the planet farthest from the son e. any planet, for they all move at the same speed

b

There are no tides to be seen in the community swimming pull because a. gravitation on the small mass of water is negligibly small b. all parts of it are practically the same distance from the moon c. it is shallow compared to the ocean d. But there are at night time e. they are masked by the much stronger pull of earth gravity

b

Toss a baseball bat into the air and it wobbles around its a. geometrical center b. center of mass c. heavier end

b

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

b

When a twirling ice skater brings her arms inward, her rotational speed a. decreases b. increases c. remains the same

b

When an iron ring is heated, the hole becomes a. neither smaller nor larger b. larger c. either smaller or larger, depending on the ring thickness d. smaller

b

A 2000-kg car experiences a braking force of 10,000 N and skids to a stop in 3 seconds. The speed of the car just before the brakes were applied was a. 30 m/s. b. 1.2 m/s. c. 15 m/s. d. none of these e. 45 m/s.

c

A TV set is pushed a distance of 2 m with a force of 20 N. How much work is done on the set? a. 800J b. 10J c. 40J d. 2J e. 20J

c

A ball player wishes to determine pitching speed by throwing a ball horizontally from an elevation of 5 m above the ground. The player sees the bad land 20 m down range. What is the players pitching speed a. none of these b. about 25 m/s c. about 20 m/s d. about 5 m/s e. about 10 m/s

c

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, the acceleration of a. the fired bullet is greater. b. the dropped bullet is greater. c. each bullet is 9.8 meters per second per second.

c

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 a. equal to its weight divided by its mass. b. equal to its weight. c. zero. d. equal to the product of its mass times its weight.

c

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 a. 800N b. none of these c. 400 N d. 1600 N e. 200 N

c

A rock is thrown vertically into the air. at the top of its path, its acceleration is a. between 0 and 10 m/s^2 b. grater than 10 m/s^2 c. 10 m/s^2 d. 0

c

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. 3N b. 8N c. 2N d. 5N e. none of these

c

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 a. 3 m/s. b. 8 m/s. c. none of these d. 6 m/s. e. 4 m/s.

c

About how high can water be theoretically lifted by a vacuum pump at lea level a. less than 10.3 m b. more than 10.3 m c. 10.3 m

c

An airplane flies at 40 m/s at an altitude of 50 meters. The pilot drops a heavy package which falls to the ground. Where, approximately, does the package land relative to the plane's new position? a. none of these b. 500 m behind the plane c. beneath the plane d. 400 m behind the plane e. more than 500 m behind the plane

c

An asteroid exerts a 360 N gravitational force on a nearby spacecraft. If the spacecraft moves to a point 3 times as far from the center of the asteroid, the force will be a. 1080 N b. 360 N c. 40 N d. 0 e. 120 N

c

Suppose a particle is being accelerated through space by a 10-N force. Suddenly the particle encounters a second force of 10 N in the opposite direction from the first force. The particle with both forces acting on it a. decelerates gradually to a halt. b. none of these c. continues at the speed it had when it encountered the second force. d. theoretically tends to accelerate toward the speed of light. e. is brought to a rapid halt.

c

Suppose you are served coffee at a restaurant before you are ready to drink it. In order for it to be the hottest when you are ready for it, you should add cream a. when you are ready to drink the coffee b. at any time c. right away

c

Toss a baseball bat into the air and it wobbles about its a. geometrical center b. heavier end c. center of mass

c

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

c

When a rocket ship gaining speed in outer space runs out of fuel, it a. gains speed for a short time, then slows down to a constant velocity b. gains speed for a short time, slows down, and eventually stops c. no longer gains speed

c

When a twirling ice skater brings her arms inward, her rotational speed a. decreases. b. remains the same. c. increases.

c

When water at 4 degrees C is heated it expands. When water at 4 degrees C is cooled, it a. neither contracts nor expands b. contracts c. expands

c

Which moves faster in m/s on a merry go round: a horse on the inside or a house on the outside near the outer rail? a. inside b. both move at the same speed in m/s c. outside

c

Without air resistance, a projectile fired horizontally at 8 km/s from atop a mountain will a. return later to its starting position and repeat its falling behavior b. none of these c. all of these d. trace a curve that matches the earth's curvature e. accelerate downward at g as it moves horizontally

c

the distance a freely falling bowling ball falls each second a. is about 10 m b. is about 5 m c. increases d. none of the above

c

A ball rolling down an incline has its max kinetic energy at a. 3/4 the way down b. halfway down c. the top d. the bottom

d

A block pulled to the left with 15 N and to the right with 5 n at the same time experiences a net force of a. 5 N b. 20 N c. 15 N d. 10 N

d

A clerk can lift cylindrical packages 1 meter vertically, or can roll them up a 2 meter long ramp to the same elevation. With the ramp, the applied force required is about a. the same b. twice as much c. four times as much d. half as much

d

A completely submerged object always displaces its own a. non elf these b. all of these c. density of fluid d. volume of fluid e. weight of fluid

d

A skydiver's terminal velocity will be greatest if she falls a) lying flat on her stomach. b) lying flat on her back. c) with her parachute open. d) head first.

d

A temperature difference of 10 degrees celsius is also equal to a temperature difference of 10 on the a. neither of these b. both of these c. Fahrenheit scale d. Kelvin scale

d

After the best physics test ever you decided to drive around the 440 beltline to enjoy your greatness. You make one rotation around the 30 mile beltline in 30 minutes. What is your average velocity? a. 30 miles/hour. b. 60 miles/hour. c. 30 m/s. d. 0 miles/hour. e. None of these choices are correct.

d

At one instant an object in free fall is moving downward at 50 m/s. One second later its speed is a. 55 m/s b. 50 m/s c. 25 m/s d. 60 m/s e. 100 m/s

d

Compared to the mass of a certain object on earth, the mass of the same object on the moon is a. 1/6 as much b. 6 times as much c. 0 d. the same

d

If a rocket initially at rest accelerates at a rate of 50 m/s^2 for one minute, its speed will be a. 500 m/s b. 50 m/s c. 3600 m/s d. 3000 m/s

d

If an object of constant mass experiences a constant net force, it will have a constant a. velocity. b. speed. c. position. d. acceleration. e. more than one of these

d

If the sun were twice as massive a. the pull of the earth on the sun would double b. its pull on the earth would double c. neither of these d. both of these

d

Objects that radiate relatively well a. neither of these b. both of these c. reflect radiation relatively well d. absorb radiation relatively well

d

Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car's acceleration in meters per second per second? a. 10 b. 40 c. 2.8 d. 4.0 e. 0.25

d

The average braking force of a 1000 kg car moving at 10 m/s braking to a stop in 5 s is a. 3000 N b. 1000 N c. 5000 N d. 2000 N e. 4000 N

d

The main reason ocean tides exist is that the pull of the mood a. and the sun on the oceans are in opposite directions b. and sun are in conjunction at high tides and in opposition at low tides c. is greater on the earth because the moon is closer to earth d. is greater on oceans closer to the moon and less on oceans farther from the moon e. none of these

d

Two identical objects in outer space, one moving at 2 m/s, the other at 1 m/s, have a head-on collision and stick together. Their combined speed after the collision is a. 1 m/s b. 0.67 m/s c. 0.33 m/s d. none of the above

d