Question 1

The Earth is 93.0 million miles from the Sun and its period of revolution is 1 year = 3.15 × 107 s.What is the acceleration of the Earth in its orbit about the Sun?

Accepted Answer

A) 18.6 mi/s2 
B) 9.30 × 10−3 mi/s2 
C) 13.6 × 10−6 mi/s2 
D) 3.70 × 10−6 mi/s2

Question 2

A 0.150-m-radius grinding wheel starts at rest and develops an angular speed of 12.00 rad/s in 7.80 s.What is the average tangential acceleration of a point on the wheel's edge?

Accepted Answer

A) 0.231 m/s2 
B) 1.54 m/s2 
C) 10.3 m/s2 
D) 14.0 m/s2

Question 3

A ceiling fan is turned on and reaches an angular speed of 132 rev/min in 20 s.It is then turned off and coasts to a stop in an additional 40 s.The ratio of the average angular acceleration for the first 20 s to that for the last 40 s is which of the following?

Accepted Answer

A) 6.6 
B) 6.4 
C) −0.15 
D) −2.0

Question 4

A bucket in an old well is hoisted upward by a rope which winds up on a cylinder having a radius of 0.050 m.How many rev/s must the cylinder turn if the bucket is raised at a speed of 0.15 m/s?

Accepted Answer

A) 3.0 rev/s 
B) 1.5 rev/s 
C) 0.48 rev/s 
D) 0.24 rev/s

Question 5

An asteroid has a perihelion (the orbit's closest approach to the Sun)of 1.5 AU and a period of revolution of 8.0 yr.What is its greatest distance from the Sun (its aphelion)?

Accepted Answer

A) 8.0 AU 
B) 6.5 AU 
C) 4.0 AU 
D) 2.5 AU

Question 6

What angular speed (in revolutions/second)is needed for a centrifuge to produce an acceleration of 1 000 g at a radius arm of 15.0 cm?

Accepted Answer

A) 40.7 rev/s 
B) 75.4 rev/s 
C) 81.4 rev/s 
D) 151 rev/s

Question 7

Starting from rest,a wheel undergoes constant angular acceleration for a period of time T.At what time after the start of rotation does the wheel reach an angular speed equal to its average angular speed for this interval?

Accepted Answer

A) 0.25T 
B) 0.50T 
C) 0.67T 
D) 0.71T

Question 8

A circular disk is rotating about a central axis with an angular velocity which is increasing at a constant rate.Point 1 on the disk is located at a distance r1 from the center of the disk and point 2 on the disk is located at a distance r2 from the center of the disk.If r2 = 2r1,which of the following ratios is the largest? 1 and 2 refer to being at points 1 and 2 in the subscripts below,all values occurring at the same time.​

Accepted Answer

A) ω2/ω1 
B) α2/α1 
C) ac2/ac1 
D) All the ratios are 1 so none is larger.

Question 9

An Earth satellite is orbiting at a distance from the Earth's surface equal to one Earth radius (4 000 miles).At this location,the acceleration due to gravity is what factor times the value of g at the Earth's surface?

Accepted Answer

A) There is no acceleration since the satellite is in orbit. 
B) 2 
C) 1/2 
D) 1/4

Question 10

Of the eight known planets in our solar system,the innermost is Mercury.When compared to the other planets in the system,Mercury has the:

Accepted Answer

A) greatest centripetal acceleration. 
B) greatest period of revolution. 
C) smallest angular velocity. 
D) smallest tangential velocity.

Question 11

How many revolutions per second are needed for a centrifuge to produce an acceleration of 1 200g at a radius arm of 15.0 cm?

Accepted Answer

A) 0.0280 rev/s 
B) 44.6 rev/s 
C) 14.2 rev/s 
D) 6.68 rev/s

Question 12

Starting from rest,a wheel undergoes constant angular acceleration for a period of time T.At which of the following times does the average angular acceleration equal the instantaneous angular acceleration?

Accepted Answer

A) 0.50T 
B) 0.67T 
C) 0.71T 
D) all of the above

Question 13

A fan blade,initially at rest,rotates with a constant acceleration of 0.025 rad/s2.What is its angular speed at the instant it goes through an angular displacement of 7.00 rad?

Accepted Answer

A) 280 rad/s 
B) 0.175 rad/s 
C) 0.592 rad/s 
D) 880 rad/s

Question 14

A 0.30-kg rock is swung in a circular path and in a vertical plane on a 0.25-m-length string.At the top of the path,the angular speed is 12.0 rad/s.What is the tension in the string at that point?

Accepted Answer

A) 7.9 N 
B) 16 N 
C) 18 N 
D) 83 N

Question 15

Somewhere between the Earth and the Moon is a point where the gravitational attraction of the Earth is canceled by the gravitational pull of the Moon.The mass of the Moon is 1/81 that of the Earth.How far from the center of the Earth is this point?

Accepted Answer

A) 8/9 the way to the Moon 
B) 9/10 the way to the Moon 
C) 3/4 the way to the Moon 
D) 80/81 the way to the Moon

Question 16

A cylindrical space colony 8.00 km in diameter and 30.0 km long has been proposed as living quarters for future space explorers.Such a habitat would have cities,land,and lakes on the inside surface and air and clouds in the center.All this would be held in place by the rotation of the cylinder about the long axis.How fast would such a cylinder have to rotate to produce a 1-g gravitational field at the walls of the cylinder?

Accepted Answer

A) 0.049 rad/s 
B) 0.035 rad/s 
C) 0.0025 rad/s 
D) 0.15 rad/s

Question 17

A ventilation fan has blades 0.25 m long rotating at 20 rpm.What is the centripetal acceleration of a point on the outer tip of a blade?

Accepted Answer

A) 1.1 m/s2 
B) 0.87 m/s2 
C) 0.55 m/s2 
D) 0.23 m/s2

Question 18

An object weighs 300 N.If the gravitational constant G were half of what it is currently,what would the weight of the object be?

Accepted Answer

A) 300 N 
B) 150 N 
C) 75 N 
D) 600 N 
E) ​450 N

Question 19

An object when orbiting the Earth at a height of three Earth radii from the center of the Earth has a weight of 2.0 N.What is the object's mass? (g at the surface of the Earth is 9.80 m/s2)

Accepted Answer

A) 0.22 kg 
B) 18 kg 
C) 1.8 kg 
D) 0.46 kg

Question 20

​Pierre performs a maneuver with his yo-yo called "around the world",where he swings the yo-yo in a vertical circle.When the yo-yo is at its highest point,which forces provide the centripetal acceleration?

Accepted Answer

A) ​friction 
B) ​gravity 
C) ​normal force 
D) ​tension 
E) ​Two of the above choices are correct.

Exam 7: Rotational Motion and Gravitation

The Earth is 93.0 million miles from the Sun and its period of revolution is 1 year = 3.15 × 10⁷ s.What is the acceleration of the Earth in its orbit about the Sun?

A 0.150-m-radius grinding wheel starts at rest and develops an angular speed of 12.00 rad/s in 7.80 s.What is the average tangential acceleration of a point on the wheel's edge?

A ceiling fan is turned on and reaches an angular speed of 132 rev/min in 20 s.It is then turned off and coasts to a stop in an additional 40 s.The ratio of the average angular acceleration for the first 20 s to that for the last 40 s is which of the following?

A bucket in an old well is hoisted upward by a rope which winds up on a cylinder having a radius of 0.050 m.How many rev/s must the cylinder turn if the bucket is raised at a speed of 0.15 m/s?

An asteroid has a perihelion (the orbit's closest approach to the Sun) of 1.5 AU and a period of revolution of 8.0 yr.What is its greatest distance from the Sun (its aphelion) ?

What angular speed (in revolutions/second) is needed for a centrifuge to produce an acceleration of 1 000 g at a radius arm of 15.0 cm?

Starting from rest,a wheel undergoes constant angular acceleration for a period of time T.At what time after the start of rotation does the wheel reach an angular speed equal to its average angular speed for this interval?

An Earth satellite is orbiting at a distance from the Earth's surface equal to one Earth radius (4 000 miles) .At this location,the acceleration due to gravity is what factor times the value of g at the Earth's surface?

Of the eight known planets in our solar system,the innermost is Mercury.When compared to the other planets in the system,Mercury has the:

How many revolutions per second are needed for a centrifuge to produce an acceleration of 1 200g at a radius arm of 15.0 cm?

Starting from rest,a wheel undergoes constant angular acceleration for a period of time T.At which of the following times does the average angular acceleration equal the instantaneous angular acceleration?

A fan blade,initially at rest,rotates with a constant acceleration of 0.025 rad/s².What is its angular speed at the instant it goes through an angular displacement of 7.00 rad?

A 0.30-kg rock is swung in a circular path and in a vertical plane on a 0.25-m-length string.At the top of the path,the angular speed is 12.0 rad/s.What is the tension in the string at that point?

Somewhere between the Earth and the Moon is a point where the gravitational attraction of the Earth is canceled by the gravitational pull of the Moon.The mass of the Moon is 1/81 that of the Earth.How far from the center of the Earth is this point?

A ventilation fan has blades 0.25 m long rotating at 20 rpm.What is the centripetal acceleration of a point on the outer tip of a blade?

An object weighs 300 N.If the gravitational constant G were half of what it is currently,what would the weight of the object be?

An object when orbiting the Earth at a height of three Earth radii from the center of the Earth has a weight of 2.0 N.What is the object's mass? (g at the surface of the Earth is 9.80 m/s²)

Pierre performs a maneuver with his yo-yo called "around the world",where he swings the yo-yo in a vertical circle.When the yo-yo is at its highest point,which forces provide the centripetal acceleration?

Exam 7: Rotational Motion and Gravitation

The Earth is 93.0 million miles from the Sun and its period of revolution is 1 year = 3.15 × 107 s.What is the acceleration of the Earth in its orbit about the Sun?

A 0.150-m-radius grinding wheel starts at rest and develops an angular speed of 12.00 rad/s in 7.80 s.What is the average tangential acceleration of a point on the wheel's edge?

A ceiling fan is turned on and reaches an angular speed of 132 rev/min in 20 s.It is then turned off and coasts to a stop in an additional 40 s.The ratio of the average angular acceleration for the first 20 s to that for the last 40 s is which of the following?

A bucket in an old well is hoisted upward by a rope which winds up on a cylinder having a radius of 0.050 m.How many rev/s must the cylinder turn if the bucket is raised at a speed of 0.15 m/s?

An asteroid has a perihelion (the orbit's closest approach to the Sun) of 1.5 AU and a period of revolution of 8.0 yr.What is its greatest distance from the Sun (its aphelion) ?

What angular speed (in revolutions/second) is needed for a centrifuge to produce an acceleration of 1 000 g at a radius arm of 15.0 cm?

Starting from rest,a wheel undergoes constant angular acceleration for a period of time T.At what time after the start of rotation does the wheel reach an angular speed equal to its average angular speed for this interval?

An Earth satellite is orbiting at a distance from the Earth's surface equal to one Earth radius (4 000 miles) .At this location,the acceleration due to gravity is what factor times the value of g at the Earth's surface?

Of the eight known planets in our solar system,the innermost is Mercury.When compared to the other planets in the system,Mercury has the:

How many revolutions per second are needed for a centrifuge to produce an acceleration of 1 200g at a radius arm of 15.0 cm?

Starting from rest,a wheel undergoes constant angular acceleration for a period of time T.At which of the following times does the average angular acceleration equal the instantaneous angular acceleration?

A fan blade,initially at rest,rotates with a constant acceleration of 0.025 rad/s2.What is its angular speed at the instant it goes through an angular displacement of 7.00 rad?

A 0.30-kg rock is swung in a circular path and in a vertical plane on a 0.25-m-length string.At the top of the path,the angular speed is 12.0 rad/s.What is the tension in the string at that point?

Somewhere between the Earth and the Moon is a point where the gravitational attraction of the Earth is canceled by the gravitational pull of the Moon.The mass of the Moon is 1/81 that of the Earth.How far from the center of the Earth is this point?

A ventilation fan has blades 0.25 m long rotating at 20 rpm.What is the centripetal acceleration of a point on the outer tip of a blade?

An object weighs 300 N.If the gravitational constant G were half of what it is currently,what would the weight of the object be?

An object when orbiting the Earth at a height of three Earth radii from the center of the Earth has a weight of 2.0 N.What is the object's mass? (g at the surface of the Earth is 9.80 m/s2)

​Pierre performs a maneuver with his yo-yo called "around the world",where he swings the yo-yo in a vertical circle.When the yo-yo is at its highest point,which forces provide the centripetal acceleration?

The Earth is 93.0 million miles from the Sun and its period of revolution is 1 year = 3.15 × 10⁷ s.What is the acceleration of the Earth in its orbit about the Sun?

A fan blade,initially at rest,rotates with a constant acceleration of 0.025 rad/s².What is its angular speed at the instant it goes through an angular displacement of 7.00 rad?

An object when orbiting the Earth at a height of three Earth radii from the center of the Earth has a weight of 2.0 N.What is the object's mass? (g at the surface of the Earth is 9.80 m/s²)

Pierre performs a maneuver with his yo-yo called "around the world",where he swings the yo-yo in a vertical circle.When the yo-yo is at its highest point,which forces provide the centripetal acceleration?