Download Circular Review with Ans - Physics 12

Base your answers to questions 1 through 3 on the
diagram below which represents a 2.0-kilogram mass
moving in a circular path on the end of a string 0.50
meter long. The mass moves in a horizontal plane at a
constant speed of 4.0 meters per second.
1. The speed of the mass is changed to 2.0 meters
per second. Compared to the centripetal
acceleration of the mass when moving at 4.0
meters per second, its centripetal acceleration
when moving at 2.0 meters per second would be
(1) half as great
(3) one-fourth as great
(2) twice as great
(4) four times great
2. The force exerted on the mass by the string is
(1) 8 N
(3) 32 N
(2) 16 N
(4) 64 N
3. The centripetal force acting on the mass is
directed toward point
(1) A
(3) C
(2) B
(4) D
4. An object travels in a circular path of radius 5.0
meters at a uniform speed of 10. meters per
second. What is the magnitude of the object's
centripetal acceleration?
(1) 10.0 m/s2
(2) 2.0 m/s2
(3) 5.0 m/s2
(4) 20. m/s2
Base your answers to questions 5 and 6 on the
diagram below which represents a ball of mass M
attached to a string. The ball moves at a constant
speed around a flat horizontal circle of radius R.
5. If the velocity of the ball is doubled, the
centripetal acceleration
(1) is halved
(3) remains the same
(2) is doubled
(4) is quadrupled
6. The centripetal acceleration of the ball is
(1) zero
(2) constant in direction, but changing in
magnitude
(3) constant in magnitude, but changing in
direction
(4) changing in both magnitude and direction
7. A 3.0-kilogram mass is traveling in a circle of
0.20-meter radius with a speed of 2.0 meters per
second. What is its centripetal acceleration?
(1) 10. m/s2
(2) 20. m/s2
(3) 60. m/s2
(4) 6.0 m/s2
8. If the velocity of a car traveling around a
circular track doubles, its centripetal
acceleration would be
(1) 1/2 as great
(3) 1/4 as great
(2) 2 times greater
(4) 4 times greater
Base your answers to questions 9 through 13 on the
diagram below which represents a 5.0-kilogram
object revolving around a circular track in a
horizontal plane at a constant speed. The radius of the
track is 20. meters and the centripetal force on the
object is 4.0 × 102 Newtons.
Base your answers to questions 15 and 16 on the
diagram below which represents a 4.0 × 10
2
-kilogram satellite, S, in a circular orbit at an altitude
of 5.0 × 106 meters. The orbital speed of the satellite
is 6.0 × 103 meters per second and the radius of the
Earth, R, is 6.4 × 106 meters.
15. The centripetal acceleration of the satellite is
closest to
(1) 9.8 m/s2
(2) 4.9 m/s2
(3) 3.2 m/s2
(4) 1.6 m/s2
9. The object's centripetal acceleration is
(1) 0.012 m/s²
(2) 20. m/s²
(3) 80. m/s²
(4) 1.0 × 102 m/s2
10. In the position shown, the object's centripetal
acceleration is directed toward point
(1) A
(3) C
(2) B
(4) D
11. The object's speed is
(1) 20. m/s
(2) 40. m/s
(3) 60. m/s
(4) 80. m/s
16. If the altitude of the satellite decreased, its
centripetal acceleration would
(1) decrease
(3) remain the same
(2) increase
17. Base your answer to the following question on
on the information and diagram below.
A 60.-kilogram adult and a 30.kilogram child are passengers on a rotor
ride at an amusement park. When the
rotating hollow cylinder reaches a
certain constant speed, v, the floor
moves downward. Both passengers stay
"pinned" against the wall of the rotor, as
shown in the diagram below.
12. If the radius of the track is increased, the
centripetal force necessary to keep the object
revolving at the same speed would
(1) decrease
(3) remain the same
(2) increase
13. In the position shown, the object's velocity is
directed toward point
(1) A
(3) C
(2) B
(4) D
14. Weightlessness is a condition in which an object
and its environment have the same
(1) mass
(3) acceleration
(2) weight
(4) speed
Compared to the magnitude of the acceleration
of the adult, the magnitude of the acceleration of
the child is
(1) less
(3) the same
(2) greater
18. Base your answer to the following question on
the following information. The diagram shows
a 5.0-kilogram cart traveling clockwise in a
horizontal circle of radius 2.0 meters at a
constant speed of 4.0 meters per second.
If the mass of the cart was doubled, the
magnitude of the centripetal acceleration of the
cart would be
(1) unchanged
(3) halved
(2) doubled
(4) quadrupled
19. Base your answer to the following question on
the diagram below which shows the path of an
object moving counterclockwise in a circle of
radius 2.0 meters. The speed of the object is 6.0
meters per second and the mass of the object is
0.2 kilogram.
What is the magnitude of the acceleration of the
object?
(1) 6.0 m/sec2
(2) 12 m/sec2
(3) 3.0 m/sec2
(4) 18 m/sec2
Base your answers to questions 20 and 21 on the
information and diagram below.
A 4.0-kilogram model airplane travels in a
horizontal circular path of radius 12 meters at
a constant speed of 6.0 meters per second.
20. What is the magnitude of the centripetal
acceleration of the airplane?
(1) 0.50 m/s2
(2) 2.0 m/s2
(3) 3.0 m/s2
(4) 12 m/s2
21. At the position shown, what is the direction of
the net force acting on the airplane?
(1) north
(3) east
(2) south
(4) west
22. An amusement park ride moves a rider at a
constant speed of 14 meters per second in a
horizontal circular path of radius 10. meters.
What is the rider's centripetal acceleration in
terms of g, the acceleration due to gravity?
(1) 1g
(3) 3g
(2) 2g
(4) 0g
23. An object traveling with uniform circular
motion has a centripetal acceleration due to the
change in
(1) speed
(3) kinetic energy
(2) direction
(4) mass
24. Base your answer to the following question on
the diagram and information below.
At an amusement park, a passenger
whose mass is 50. kilograms rides in a
cage. The cage has a constant speed of
10. meters per second in a vertical
circular path of radius R, equal to 10.
meters.
26. Base your answer to the following question on
the diagram below which shows a 2.0-kilogram
cart traveling at a constant speed in a horizontal
circle of radius 3.0 meters. The magnitude of the
centripetal force of the cart is 24 Newtons.
In the position shown, the acceleration of the
cart is
(1) 8.0 m/s2 directed toward point A
(2) 8.0 m/s2 directed toward point D
(3) 12 m/s2 directed toward point A
(4) 12 m/s2 directed toward point D
What is the magnitude of the centripetal
acceleration of the passenger?
(1) 1.0 m/s2
(2) 2.0 × 103 m/s2
(3) 5.0 × 102 m/s2
(4) 10. m/s2
27. Base your answer to the following question on
the diagram below which represents a mass of
10.0 kilograms traveling at constant speed of 4.
meters per second in a horizontal circular path
about point D.
25. Base your answer to the following question on
the information below.
A 2.0 × 103-kilogram car travels at a
constant speed of 12 meters per second
around a circular curve of radius 30.
meters.
What is the magnitude of the centripetal
acceleration of the car as it goes around the
curve?
(1) 0.40 m/s2
(2) 4.8 m/s2
(3) 800 m/s2
(4) 9,600 m/s2
If the 10.-kilogram mass is replaced with a
greater mass, the centripetal acceleration will
(1) decrease
(3) remain the same
(2) increase
Base your answers to questions 28 and 29 on the
information and diagram below.
The diagram shows a student seated on a
rotating circular platform, holding a 2.0kilogram block with a spring scale. The block
is 1.2 meters from the center of the platform.
The block has a constant speed of 8.0 meters
per second. [Frictional forces on the block
are negligible.]
28. The reading on the spring scale is approximately
(1) 20. N
(3) 110 N
(2) 53 N
(4) 130 N
29. Which statement best describes the block’s
movement as the platform rotates?
(1) Its velocity is directed tangent to the circular
path, with an inward acceleration.
(2) Its velocity is directed tangent to the circular
path, with an outward acceleration.
(3) Its velocity is directed perpendicular to the
circular path, with an inward acceleration.
(4) Its velocity is directed perpendicular to the
circular path, with an outward acceleration.
30. As the time taken for a car to make one lap
around a circular track decreases, the centripetal
acceleration of the car
(1) decreases
(3) remains the same
(2) increases
31. A satellite is in geosynchronous orbit. Compared
to Earth’s period of rotation, the satellite’s
period of revolution is
(1) less
(3) the same
(2) greater
Base your answers to questions 32 and 33 on the
diagram below which shows an object with a mass of
1.0 kilogram attached to a string 0.50 meter long. The
object is moving at a constant speed of 5.0 meters per
second in a horizontal circular path with center at
point O.
32. While the object is undergoing uniform circular
motion, its acceleration
(1) has a magnitude of zero
(2) increases in magnitude
(3) is directed toward the center of the circle
(4) is directed away from the center of the circle
33. If the string is cut when the object is at the
position shown, the path the object will travel
from this position will be
(1) toward the center of the circle
(2) a curve away from the circle
(3) a straight line tangent to the circle
34. A car going around a curve is acted upon by a
centripetal force, F. If the speed of the car were
twice as great, the centripetal force necessary to
keep it moving in the same path would be
(1) F
(3) F/2
(2) 2F
(4) 4F
35. A motorcycle travels around a flat circular track.
If the speed of the motorcycle is increased, the
force required to keep it in the same circular path
(1) decreases
(3) remains the same
(2) increases
36. The diagram below represents a ball undergoing
uniform circular motion as it travels clockwise
on a string.
Base your answers to questions 38 through 40 on the
information and diagram below.
A 1.00 × 103 -kilogram car is driven
clockwise around a flat circular track of
radius 25.0 meters. The speed of the car is a
constant 5.00 meters per second.
At the moment shown in the diagram, what are
the correct directions of both the velocity and
centripetal acceleration of the ball?
(1)
(2)
(3)
(4)
37. A car rounds a horizontal curve of constant
radius at a constant speed. Which diagram best
represents the directions of both the car’s
velocity, v, and acceleration, a?
38. At the instant shown in the diagram, the car’s
centripetal acceleration is directed
(1) toward E
(3) toward W
(2) toward N
(4) clockwise
39. What minimum friction force must exist
between the tires and the road to prevent the car
from skidding as it rounds the curve?
(1) 1.25 × 105 Ν
(2) 9.80 × 104 Ν
(3) 5.00 × 103 Ν
(4) 1.00 × 103 Ν
(1)
(3)
40. Which factor, when doubled, would produce the
greatest change in the centripetal force acting on
the car?
(1) mass of the car
(3) velocity of the car
(2) radius of the track (4) weight of the car
(2)
(4)
41. In order to experience weightlessness in a
spaceship, an astronaut must have an
acceleration that is
(1) less than that of the ship
(2) more than that of the ship
(3) the same as that of the ship
Base your answers to questions 42 and 43 on the
information and diagram below.
The diagram shows the top view of a 65kilogram student at point A on an amusement
park ride. The ride spins the student in a
horizontal circle of radius 2.5 meters, at a
constant speed of 8.6 meters per second. The
floor is lowered and the student remains
against the wall without falling to the floor.
42. Which vector best represents the direction of the
centripetal acceleration of the student at point A.
(1)
(2)
(3)
(4)
43. The magnitude of the centripetal force acting on
the student at point A is approximately
(1) 1.2 × 104 N
(2) 1.9 × 103 N
(3) 2.2 × 102 N
(4) 3.0 × 101 N
Base your answers to questions 45 and 46 on on the
information and diagram below.
A vehicle travels at a constant speed of
6.0 meters per second around a horizontal
circular curve with a radius of 24 meters. The
mass of the vehicle is 4.4 × 103 kilograms.
An icy patch is located at P on the curve.
45. What is the magnitude of the frictional force that
keeps the vehicle on its circular path?
(1) 1.1 × 103 N
(2) 6.6 × 103 N
(3) 4.3 × 104 N
(4) 6.5 × 104 N
46. On the icy patch of pavement, the frictional
force on the vehicle is zero. Which arrow best
represents the direction of the vehicle's velocity
when it reaches icy patch P?
(1)
(3)
(2)
44. The path of one body moving about another in
space is
(1) centripetal acceleration
(2) centripetal force
(3) an orbit
(4) a period
(4)
47. The diagram below shows a satellite of mass m
orbiting Earth in a circular path of radius R.
Base your answers to questions 50 and 51 on the
information and diagram below.
A roller coaster cart starts from rest and
accelerates, due to gravity, down a track. The
cart starts at a height that enables it to
complete a loop in the track. [Neglect
friction.]
If centripetal force Fc, is acting on the satellite,
its speed is equal to
(1)
(3)
(2)
(4)
48. A ball of mass M at the end of a string is
swinging in a horizontal circular path of radius R
at constant speed V. Which combination of
changes would require the greatest increase in
the centripetal force acting on the ball?
(1) doubling V and doubling R
(2) doubling V and halving R
(3) halving V and doubling R
(4) halving V and halving R
49. Which condition represents uniform circular
motion?
(1) a phonograph turntable that increases its
rotation rate
(2) a comet in elliptical orbit about the Sun
(3) a racer running at constant speed on a
circular track
(4) a fan blade as it slows down when turned off
50. The magnitude of the centripetal force keeping
the cart in circular motion would be greatest at
point
(1) A
(3) C
(2) B
(4) D
51. Which diagram best represents the path
followed by an object that falls off the cart when
the cart is at point D?
(1)
(2)
(3)
(4)
52. What would occur as a result of the frictional
drag of the atmosphere on an artificial satellite
orbiting the Earth?
(1) The satellite would increase in speed and
escape the gravitational field of the Earth.
(2) The satellite would increase in speed and
spiral toward the Earth.
(3) The satellite would decrease in speed and
escape the gravitational field of the Earth.
(4) The satellite would decrease in speed and
spiral toward the Earth.
53. The diagram below shows a 5.0-kilogram bucket
of water being swung in a horizontal circle ofmeter radius at a constant speed of 2.0 meters
per second.
The magnitude of the centripetal force on the
bucket of water is approximately
(1) 5.7 N
(3) 29 N
(2) 14 N
(4) 200 N
54. A satellite is moving at constant speed in a
circular orbit about the Earth, as shown in the
diagram below.
The net force acting on the satellite is directed
toward point
(1) A
(3) C
(2) B
(4) D
55. A communications satellite in geosynchronous
orbit around Earth remains over the same
location on Earth. The satellite's period of
revolution about Earth is closest to
(1) 1 hour
(3) 1 month
(2) 1 day
(4) 1 year
56. Base your answer to the following question on
the information and diagram below.
An athlete in a hammer-throw event
swings a 7.0-kilogram hammer in a
horizontal circle at a constant speed of
12 meter per second. The radius of the
hammer's path is 2.0 meters
At the position shown, the centripetal force
acting on the hammer is directed toward point
(1) A
(3) C
(2) B
(4) D
57. A satellite orbits the Earth in a circular orbit.
Which statement best explains why the satellite
does not move closer to the center of the Earth?
(1) The gravitational field of the Earth does not
reach the satellite's orbit.
(2) The Earth's gravity keeps the satellite
moving with constant velocity.
(3) The satellite is always moving
perpendicularly to the force due to gravity.
(4) The satellite does not have any weight.
58. What is the period of orbit of a communications
satellite in geosynchronous orbit about Earth?
(1) 1 year
(3) 12 hours
(2) 24 hours
(4) 60 minutes
59. The diagram below shows an object moving
counterclockwise around a horizontal, circular
track.
60. An object on the end of a
string rotates clockwise in a
circle as shown in the
diagram below.
If the string breaks when the object is at point X,
which arrow below best represents the path of
the object after the string has broken?
Which diagram represents the direction of both
the object's velocity and the centripetal force
acting on the object when it is in the position
shown?
(1)
(1)
(3)
(2)
(4)
61. A ball attached to a string is moved at constant
speed in a horizontal circular path. A target is
located near the path of the ball as shown in the
diagram.
(2)
(3)
(4)
At which point along the ball’s path should the
string be released, if the ball is to hit the target?
(1) A
(3) C
(2) B
(4) D
62. In which diagram do the arrows best represent
the path of a satellite in a geosynchronous orbit?
(figures not drawn to scale)
(3)
(1)
(2)
(4)
63. Which condition is required for a satellite to be
in a geosynchronous orbit about the Earth?
(1) The period of revolution of the satellite must
be the same as the rotational period of the
Earth.
(2) The altitude of the satellite must be equal to
the radius of the Earth.
(3) The orbital speed of the satellite around the
Earth must be the same as the orbital speed
of the Earth around the Sun.
(4) The daily distance traveled by the satellite
must be equal to the circumference of the
Earth.
Answer Key
[New Exam]
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