Py 131 Final Exam
After the semester you throw your clicker straight up. When it reaches maximum height the velocity is zero and the acceleration is (neglect air resistance)
-10 m/s/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
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?
0 mph
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
0.5 m/s
A bullet fired horizontally over level ground hits the ground in 0.5 seconds. If it had been fired with 10 times the speed in the same direction, it would have hit the ground in
0.5 s
You stand on your skateboard and exert a 50-N push on the wall next to you. If your mass is 60 kg you'll momentarily accelerate from the wall at about
0.8 m/s2
The time it takes a projectile fired straight up at 10 m/s to reach the top of its path is about
1 s
An asteroid exerts a 160-N gravitational force on a nearby spacecraft. If the spacecraft moves to a point 4 times as far from the center of the asteroid, the force will be
10 N
The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is
10 N
The support force on a 10-N book at rest on a table is
10 N
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 seconds later?
10 m
The gain in speed each second for a freely falling object is about
10 m/s
A melon is tossed straight upward with 100 J of kinetic energy. If air resistance is negligible the melon will return to its initial level with a kinetic energy of
100 J
Which could burn a boy scout the most?
100 g of steam at 100 degrees C
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
15 m/s
A car moves 4 times as fast as another identical car. Compared to the slower car, the faster car has
16 times the KE
A car traveling at 50 km/h will skid 20 m when its brakes are locked. If the same car is traveling at 150 km/h, what will be its skidding distance?
180 m
If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting point is about
2 seconds
When you walk at an average speed of 4 m/s, in 5 s you'll cover a distance of
20 m
A car as a mass of 1000kg and accelerates at 2 m/s2. What is the net force exerted on the car?
2000 N
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?
3.0
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
If a rocket initially at rest accelerates at a rate of 50 m/s2 for one minutes, its speed will be
3000 m/s
Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car's acceleration?
4.0
A TV set is pushed a distance of 2 m with a force of 20 N. How much work is done on the set?
40 J
The work done in pushing a TV set a distance of 2 m with an average force of 20 N is
40 J
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
A piece of rope is pulled by two people in a tug-of-war. Each exerts a 400 N of force. What is the tension in the rope?
400 N
A mobile phone is pulled northward by a force of 10 N and at the same time pulled southward by another force of 15 N. The resultant force on the phone is
5 N
A 5-kg fish swimming at 1 m/s swallows an absent minded 1-kg fish at rest. The speed of the larger fish after lunch is
5/6 m/s
Suzie Skydiver, who weighs 500 N, reaches terminal velocity of 90 km/h. The air resistance on Suzie is then
500 N
A 10-N falling object encounters 4 N of air resistance. The net force on the object is
6 N
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?
80 J
Which of the following is not a vector quantity?
Speed
An object is placed exactly halfway between the Earth and sun. The object will fall toward the
Sun
Near the top of a mountain, water in an open pot boils at
a lower temperature than at sea level
It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft?
about 180 m
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 ball land 20m down range. What is the player's pitching speed?
about 20 m/s
The famous Leaning Tower of Pisa doesn't topple over because its center of gravity is
above a place of support
Objects that radiate relatively well
absorb radiation relatively well
When a solid is changed to a liquid phase, the solid
absorbs energy
If an apple experiences a constant net force, it will have a constant
acceleration
If an object of constant mass experiences a constant net force, it will have a constant
acceleration
Inside a freely falling elevator, there would be no
apparent weight for you
Facts in the field of science
are changeable
If you toss a coin straight upward while in a train moving at constant velocity, the coin will land
as if you were at rest
Arnold Strongman and Suzie Small each pull very hard on opposite ends of a massless rope in a tug-of-war. The greater force on the rope is exerted by
both the same
You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum during the time of contact?
both the same
When an object is partly or wholly immersed in a liquid, it is buoyed up
by a force equal to the weight of liquid displaced
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
continues at the speed it had when it encountered the second force
When heat is added to boiling water, its temperature
does not change
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
each bullet is 9.8 meters per second per second
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
exactly below the midpoint of the ceiling
When water at 4 degrees C is heated it expands. When water at 4 degrees C is cooled, it
expands
A vehicle undergoes acceleration when it
gains speed, loses speed, and changes its direction
When a dishonest scientist reports false information, he or she
gets no second chance in the scientific community
A clerk can lift containers a vertical distance of 1 meter or can roll them up a 2 meter-long ramp to the same elevation. With the ramp, the applied force required is about
half as much
If the volume of an object were to double while its mass stays the same, its density would
halve
When Joshua brakes his speeding bicycle to a stop, kinetic energy is transformed to
heat
Newton's law of cooling applies to objects that are
heating and cooling
The moderate temperature of islands throughout the world has much to do with water's
high specific heat
An educated scientific guess is a
hypothesis
Padded dashboards in cars are safer in an accident than non-padded ones because passengers hitting the dashboard encounter
increased time of impact
When a twirling ice skater brings her arms inward, her rotational speed
increases
A ring and a disk, initially at rest, roll down a hill together. The one to reach the bottom first
is the disk
If the sun were twice as massive
its pull on the earth would double, the pull of the earth on the sun would double
A temperature difference of 10 degrees Celsius is also equal to a temperature difference of 10 on the
kelvin scale
When an iron ring is heated, the hole becomes
larger
A lobster crawls onto a bathroom scale submerged at the bottom of the ocean. Compared to its weight above the surface, the lobster will have an apparent weight under water that is
less
The faster a fluid flows, the
less its internal pressure
A substance that heats up relatively quickly has a
low specific heat
A force is a vector quantity because it has both
magnitude and direction
The buoyant force on a rock is least when the rock is submerged
near the bottom, near the surface, halfway to the bottom
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
none of these (9 m/s)
Which of the following is absolute and can never be questioned?
nonsense, they can all be proven wrong
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?
outside horse
Without air resistance, a projectile fired horizontally at 8 km/s from a mountaintop will
return later to its starting point and repeat its falling behavior, accelerate downward at g as it moves horizontally, trace a curve that matches the earth's curvature
A ring and a disk both at rest roll down a hill together. Which rolls slower?
ring
A black hole is
simply the remains of a giant star that has undergone gravitational collapse
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 it's flight while its rotational speed
slows
The rotational inertia of your leg is greater when your leg is
straight
A ball rolling down an incline has its maximum kinetic energy at
the bottom
Both a 50-kg sack is lifted 2 meters from the ground and a 25-kg sack is lifted 4 meters in the same time. The power expended in raising the 50-kg sack is
the same
Compared to the mass of a certain object on Earth, the mass of the same object on the moon is
the same
Compared to the mass of an apple on Earth, the mass of the apple on the Moon is
the same
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
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
the same for each bullet
To catch a fast-moving ball, you extend your hand forward before contact with the ball and let it ride backward in the direction of the ball's motion. Doing this reduces the force of contact on your hand principally because the
time of contact is increased
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
tw0
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
twice
An object lifted 10 meters gains 200 J of potential energy. If the same object is lifted 20 meters, its potential energy gain is
twice as much
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
The cooling effect inside a refrigerator is produced by
vaporizing the refrigeration liquid
A completely submerged object always displaces its own
volume of fluid
A cart maintains a constant velocity of 100 m/s for 10 seconds. During this interval its acceleration is
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
zero
When a falling object has reached its terminal velocity, its acceleration is
zero
