Transcript Slide 1

Chapters 12 and 13 Review
Questions
1. The strength of the gravitational force
between two objects depends on the
objects'
• A. masses and the distance between them
• B. weights and accelerations
• C. momentum and velocities
• D. masses and velocities
2. Joseph throws a baseball straight forward. At
the same time, Corey drops a baseball from the
same height. Which of the following is TRUE?
• A. Joseph's baseball falls faster than Corey's.
• B. Corey's baseball falls faster than Joseph's.
• C. Both baseballs fall at the same rate.
• D. You cannot predict which baseball will fall
faster.
3. A satellite in orbit
• A. is not affected by gravity
• B. is always falling toward Earth
• C. must have a speed less than 8000 m/s
• D. cannot fall more than 5 m
4. An astronaut in an orbiting spacecraft
floats because
• A. Earth's gravity is too weak to affect the
spacecraft
• B. the spacecraft and the astronaut fall at
the same rate
• C. there is no force of gravity in space
• D. the spacecraft has a low acceleration
5. Friction resists motion between
• A. any two objects
• B. surfaces in contact
• C. fluids only
• D. objects in free fall
6. Which of the following would increase the
friction between a table and the floor?
• A. pushing the table faster
• B. pushing the table slower
• C. taking heavy objects off the table
• D. putting heavy objects on the table
7. As you push an object, the frictional force
resisting your push
• A. remains constant once the object is moving
• B. continues to increase even after the object is
moving
• C. steadily decreases after the object begins to
move
• D. no longer resists once the object begins to
move
8. Air resistance increases with
• A. increased speed and decreased
surface area
• B. decreased speed and increased
surface area
• C. increased speed and increased surface
area
• D. decreased speed and decreased
surface area
9. The work a force does on an object
depends on the
• A. height of the object above the ground
• B. the size of the force and the distance it
acts over
• C. acceleration and the mass of the object
• D. the potential energy of the object
10. A classmate lifts a book 50 cm. You lift
the same book 150 cm using the same
force. Compared to your classmate, you
have done
• A. one third the work
• B. three times the work
• C. nine times the work
• D. the same amount of work
11. Work can be measured in units called
• A. newtons
• B. meters per second
• C. joules
• D. kilograms
12. Sean pushes a cart 100 m. Which of the
following statements is TRUE?
• A. The cart does work on Sean.
• B. Sean does no work.
• C. Sean does work on the cart over the
entire 100 m.
• D. Work is done only when Sean first
begins to push.
13. When Roger kicks a football, the football
gains mechanical energy because Roger
• A. does work on the football
• B. does work on the ground
• C. has more energy than the football
• D. has less energy than the football
14. Yelena holds a 5 kg ball over her head at
a height of 2 m. What is the gravitational
potential energy (GPE) of the ball? The
formula for GPE is GPE = mgh, where g =
9.8 m/s2.
• A. 5 J
• B. 9.8 J
• C. 10 J
• D. 98 J
15. Quentin has a mass of 50 kg. When he
rides his scooter at a velocity of 3 m/s,
what is his kinetic energy? The formula for
kinetic energy (KE) is KE = 1/2mv2.
• A. 50 J
• B. 75 J
• C. 225 J
• D. 450 J
16. To find the mechanical energy of an object,
• A. multiply its kinetic energy and potential
energy
• B. add its kinetic energy and potential energy
• C. divide its kinetic energy by its potential energy
• D. divide its potential energy by its kinetic energy
17. Kara does work on a ball by kicking it.
The work Kara does on the ball
• A. increases Kara's energy
• B. increases the ball's energy
• C. decreases the ball's energy
• D. decreases the ball's mass and height
18. If you double the distance over which a
force moves an object, then the work is
multiplied by
• A. 1/4
• B. 1/2
• C. 2
• D. 4
19. If you push a large rock as hard as you
possibly can, and the rock does not move,
• A. you do not use any force or do any
work on the rock
• B. you use force, but do not do any work
on the rock
• C. you do work on the rock, but do not use
force
• D. you use force and do work on the rock
20. When you do work on an object, you
transfer
• A. power
• B. velocity
• C. energy
• D. acceleration
21. Which of the following does work?
• A. a book lying on a table
• B. a person holding a book over her head
• C. a person reading a page of a book
• D. a person pushing a book across a floor
22. Which of the following will increase the
amount of work you do pushing a box?
• A. increasing the velocity of the box
• B. increasing the distance you push the
box
• C. decreasing the distance you push the
box
• D. decreasing the force you apply to the
box
23. The force that attracts two masses to
each other is called
• A. air resistance
• B. friction
• C. gravity
• D. pressure
24. A hollow plastic ball and a solid metal
ball are dropped from the same height in a
vacuum. With no air resistance, gravity is
the only force acting on the balls. What do
you predict will happen?
• A. The balls will fall at the same rate.
• B. The metal ball will fall faster.
• C. The plastic ball will fall faster.
• D. The larger ball will fall faster.
25. After a space shuttle is launched into orbit,
gravity
• A. gives it a speed greater than 11,000 m/s
• B. no longer affects the astronauts on board
• C. makes it impossible for it to stay in orbit for a
long period of time
• D. continues to pull it toward the center of Earth
26. Maria is sliding a box across the floor.
She feels the box resisting her push. The
resistance is caused by
• A. pressure
• B. friction
• C. gravity
• D. motion
27. The strength of the gravitational force
between objects depends on
• A. mass and distance
• B. pressure and area
• C. mass and volume
• D. force and acceleration
28. Without air resistance, for example, in a
vacuum, the rate of acceleration resulting from
Earth's gravity
• A. depends on the surface area of the falling
object
• B. is the same for all objects, whatever their
mass
• C. depends on the density of the falling object
• D. decreases as objects get closer to Earth
29. An astronaut in orbit experiences microgravity
because he or she
• A. is too far from Earth to be affected by gravity
• B. is falling at the same rate as the spacecraft
• C. is traveling faster than the escape velocity
• D. is accelerating fast enough to overcome
friction
30. As Eli rubs a piece of wood with
sandpaper, the wood becomes warmer.
This release of heat is due to
• A. air pressure
• B. air resistance
• C. friction
• D. gravity
30. As Eli rubs a piece of wood with
sandpaper, the wood becomes warmer.
This release of heat is due to
• A. air pressure
• B. air resistance
• C. friction
• D. gravity
31. The formula for calculating the force of
gravity on a mass close to Earth's surface
is F = mg. The g in this formula is
• A. the mass of the object in grams
• B. the speed of the object as it falls
• C. acceleration caused by Earth's gravity
• D. constant velocity caused by Earth's
gravity
32. Alison dives 5 meters below the surface of a
lake. The pressure on her
• A. decreases because under water there is no
air pressure
• B. is directed upward because some objects are
buoyant in water
• C. is directed downward because air is less
dense than water
• D. increases because of the weight of all the
water above her
33. Before doing a gymnastics routine on a
high bar, Alysha puts rosin, a sticky
substance, on her hands. She does this in
order to
• A. increase air pressure
• B. decrease air resistance
• C. decrease gravity
• D. increase friction