Physics 131 Exam 1

80 J

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? -6 J -32 J -none of these -8 J -80 J

15 m/s

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: -30 m/s -1.2 m/s -15 m/s -none of these -45 m/s

0 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 5 m/s. The speed of the shark after this meal is: -0 m/s -1/2 m/s -1/5 m/s -1/6 m/s -5/3 m/s

300 N upward

A 500 N parachutist opens his chute and experiences an air resistance force of 800 N. The net force on the parachutist is: -300 N upward -500 N upward -500 N downward -300 N downward -800 N downward

40 J

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

the bottom

A ball rolling down an incline has its maximum kinetic energy at: -3/4 of the way down -1/2 way down -the top -the bottom

each bullet is 9.8 meters per second per second

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: -the fired bullet is greater -the dropped bullet is greater -each bullet is 9.8 meters per second per second

16 times the KE

A car moves 4 times as fast as another identical car. Compared to the slower car, the faster car has: -16 times the KE -12 times the KE -8 times the KE -4 times the KE

180 m

A car moving at 50 km/hr skids 20 m with locked brakes. How far will the car skid with locked brakes if it is traveling at 150 km/hr? -60 m -180 m -20 m -120 m -90 m

the same

A clerk can lift containers a vertical distance of 1 M or can roll them up a 2 M long ramp to the same elevation. With the ramp, the applied force required is about: -half as much -four times as much -the same -twice as much

3.0

A girl 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 in meters per second per second? -300 -0.3 -10 -3.0 -30

zero

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: -equal to its weight divided by its mass -equal to its weight -zero -equal to the product of its mass times its weight

10 m

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

400 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: -800 N -none of these -400 N -1600 N -200 N

is the disk

A ring and a disk, initially at rest, roll down a hill together. The one to reach the bottom first: -both reach the bottom at the same time -is the disk -is the ring -depends on the masses -depends on the relative rotational inertias

none of these

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: -3 m/s -8 m/s -none of these -6 m/s -4m/s

exactly below the midpoint of the ceiling

A truck is moving at a 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: -behind the midpoint of the ceiling -exactly below the midpoint of the ceiling -ahead of the midpoint of the ceiling -none of these -more info is needed to solve

0 miles/hr

After the best physics tests 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? -30 miles/hr -60 miles/hr -30 m/s -0 miles/hr -none of these choices are correct

twice as much

An object lifted 10 M gains 200 J of potential energy. If the same object is lifted 20 M, its potential energy gain is: -more than four times as much -four times as much -twice as much -half as much -the same

the same

Compared to the mass of a certain object on Earth, the mass of the same object on the moon is: -one sixth as much -six times as much -zero -the same

2 seconds

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: -10 seconds -2 seconds -1 second -not enough information to estimate -20 seconds

3000 m/s

If a rocket initially at rest accelerates at a rate of 50 m/s/s for one minute, its speed will be: -3000 m/s -50 m/s -500 m/s -3600 m/s

acceleration

If an object of constant mass experiences a constant net force, it will have a constant: -velocity -speed -position -acceleration -more than one of these

about 180 m

It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft? -more than 200 m -about 120 m -about 180 m -about 60 m

increased time of impact

Padded dashboards in cars are safer in an accident than nonpadded ones because an occupant hitting the dash has: -decreased time of impact -decreased impulse -increased time of impact -increased momentum

two

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: -two -eight -four

continues at the speed it had when it encountered the second force

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: -decelerates gradually to a halt -none of these -continues at the speed it had when it encountered the second force -theoretically tends to accelerate toward the speed of light -is brought to a rapid halt

4.0

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: -10 -40 -2.8 -4.0 -0.25

the same for both

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: -the same for both -the car -more information needed -the bug

above a place of support

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

10 m/s

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

zero

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

increases

When a twirling ice skater brings her arms inward, her rotational speed: -decreases -remains the same -increases

outside horse

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

nonsense, they can all be proven wrong

Which of the following is absolute and can never be questioned? -theory -hypothesis -Keith -nonsense, they all can be proven wrong -law