Halliday/Resnick/Walker Fundamentals of Physics 8th edition Classroom Response System Questions Chapter 10 Rotation Reading Quiz Questions

10. 2. 1. Angles are often measured in radians 10.2.1. Angles are often measured in radians. How many degrees are there in one radian? a) 0.0175 b) 1.57 c) 3.14 d) 16.3 e) 57.3

10. 2. 1. Angles are often measured in radians 10.2.1. Angles are often measured in radians. How many degrees are there in one radian? a) 0.0175 b) 1.57 c) 3.14 d) 16.3 e) 57.3

10. 2. 2. The SI unit for angular displacement is the radian 10.2.2. The SI unit for angular displacement is the radian. In calculations, what is the effect of using the radian? a) Any angular quantities involving the radian must first be converted to degrees. b) Since the radian is a unitless quantity, there is no effect on other units when multiplying of dividing by the radian. c) Since the radian is a unitless quantity, any units multiplied or divided by the radian will be equal to one. d) Since the radian is a unitless quantity, the number of radians of angular displacement plays no role in the calculation. e) The result of the calculation will always have the radian among the units.

10. 2. 2. The SI unit for angular displacement is the radian 10.2.2. The SI unit for angular displacement is the radian. In calculations, what is the effect of using the radian? a) Any angular quantities involving the radian must first be converted to degrees. b) Since the radian is a unitless quantity, there is no effect on other units when multiplying of dividing by the radian. c) Since the radian is a unitless quantity, any units multiplied or divided by the radian will be equal to one. d) Since the radian is a unitless quantity, the number of radians of angular displacement plays no role in the calculation. e) The result of the calculation will always have the radian among the units.

10.2.3. For a given circle, the radian is defined as which one of the following expressions? a) the arc length divided by the radius of the circle b)  (3.141592...) times twice the radius of the circle c) two times ninety degrees divided by  (3.141592...) d) the arc length divided by the circumference of the circle e) the arc length divided by the diameter of the circle

10.2.3. For a given circle, the radian is defined as which one of the following expressions? a) the arc length divided by the radius of the circle b)  (3.141592...) times twice the radius of the circle c) two times ninety degrees divided by  (3.141592...) d) the arc length divided by the circumference of the circle e) the arc length divided by the diameter of the circle

10.2.4. The hand on a certain stopwatch makes one complete revolution every three seconds. Express the magnitude of the angular velocity of this hand in radians per second. a) 0.33 rad/s b) 0.66 rad/s c) 2.1 rad/s d) 6.0 rad/s e) 19 rad/s

10.2.4. The hand on a certain stopwatch makes one complete revolution every three seconds. Express the magnitude of the angular velocity of this hand in radians per second. a) 0.33 rad/s b) 0.66 rad/s c) 2.1 rad/s d) 6.0 rad/s e) 19 rad/s

10.2.5. A drill bit in a hand drill is turning at 1200 revolutions per minute (1200 rpm). Express this angular speed in radians per second (rad/s). a) 2.1 rad/s b) 19 rad/s c) 125 rad/s d) 39 rad/s e) 0.67 rad/s

10.2.5. A drill bit in a hand drill is turning at 1200 revolutions per minute (1200 rpm). Express this angular speed in radians per second (rad/s). a) 2.1 rad/s b) 19 rad/s c) 125 rad/s d) 39 rad/s e) 0.67 rad/s

10.2.6. Which one of the following choices is the SI unit for angular velocity? a) revolutions per minute (rpm) b) meters per second (m/s) c) degrees per minute (/min) d) radians per second (rad/s) e) tychos per second (ty/s)

10.2.6. Which one of the following choices is the SI unit for angular velocity? a) revolutions per minute (rpm) b) meters per second (m/s) c) degrees per minute (/min) d) radians per second (rad/s) e) tychos per second (ty/s)

10. 2. 7. The jet engine has angular acceleration of 2. 5 rad/s2 10.2.7. The jet engine has angular acceleration of 2.5 rad/s2. Which one of the following statements is correct concerning this situation? a) The direction of the angular acceleration is counterclockwise. b) The direction of the angular velocity must be clockwise. c) The angular velocity must be decreasing as time passes. d) If the angular velocity is clockwise, then its magnitude must increase as time passes. e) If the angular velocity is counterclockwise, then its magnitude must increase as time passes.

10. 2. 7. The jet engine has angular acceleration of 2. 5 rad/s2 10.2.7. The jet engine has angular acceleration of 2.5 rad/s2. Which one of the following statements is correct concerning this situation? a) The direction of the angular acceleration is counterclockwise. b) The direction of the angular velocity must be clockwise. c) The angular velocity must be decreasing as time passes. d) If the angular velocity is clockwise, then its magnitude must increase as time passes. e) If the angular velocity is counterclockwise, then its magnitude must increase as time passes.

10.3.1. The wheels of a bicycle roll without slipping on a horizontal road. The bicycle is moving due east at a constant velocity. What is the direction of the angular velocity of the wheels? a) down b) west c) east d) north e) south

10.3.1. The wheels of a bicycle roll without slipping on a horizontal road. The bicycle is moving due east at a constant velocity. What is the direction of the angular velocity of the wheels? a) down b) west c) east d) north e) south

10.3.2. While putting in a new ceiling, Jake uses a drill to put screws into the drywall. The screws rotate clockwise as they go into the ceiling. What is the direction of the angular velocity of the screw as the drill drives it into the ceiling? Express the direction relative to Jake, who is looking upward at the screw. a) down b) up c) left d) right e) forward

10.3.2. While putting in a new ceiling, Jake uses a drill to put screws into the drywall. The screws rotate clockwise as they go into the ceiling. What is the direction of the angular velocity of the screw as the drill drives it into the ceiling? Express the direction relative to Jake, who is looking upward at the screw. a) down b) up c) left d) right e) forward

10.4.1. Which one of the following equations is only valid when the angular measure is expressed in radians? a) b) c) d) e)

10.4.1. Which one of the following equations is only valid when the angular measure is expressed in radians? a) b) c) d) e)

10.4.2. Consider the following situation: one of the wheels of a motor cycle is initially rotating at 39 rad/s. The driver then accelerates uniformly at 7.0 rad/s2 until the wheels are rotating at 78 rad/s. Which one of the following expressions can be used to find the angular displacement of a wheel during the time its angular speed is increasing? a) b) c) d) e)

10.4.2. Consider the following situation: one of the wheels of a motor cycle is initially rotating at 39 rad/s. The driver then accelerates uniformly at 7.0 rad/s2 until the wheels are rotating at 78 rad/s. Which one of the following expressions can be used to find the angular displacement of a wheel during the time its angular speed is increasing? a) b) c) d) e)

10.5.1. A deep space probe is rotating about a fixed axis with a constant angular acceleration. Which one of the following statements concerning the tangential acceleration component of any point on the probe is true? a) The probe’s tangential acceleration component is constant in both magnitude and direction. b) The magnitude of the probe’s tangential acceleration component is zero m/s2. c) The tangential acceleration component depends on the angular velocity of the probe. d) The tangential acceleration component is to equal the radial acceleration of the probe. e) The tangential acceleration component depends on the change in the probe’s angular velocity.

10.5.1. A deep space probe is rotating about a fixed axis with a constant angular acceleration. Which one of the following statements concerning the tangential acceleration component of any point on the probe is true? a) The probe’s tangential acceleration component is constant in both magnitude and direction. b) The magnitude of the probe’s tangential acceleration component is zero m/s2. c) The tangential acceleration component depends on the angular velocity of the probe. d) The tangential acceleration component is to equal the radial acceleration of the probe. e) The tangential acceleration component depends on the change in the probe’s angular velocity.

10.5.2. Two points are located on a rigid wheel that is rotating with a decreasing angular velocity about a fixed axis. Point A is located on the rim of the wheel and point B is halfway between the rim and the axis. Which one of the following statements is true concerning this situation? a) Both points have the same radial acceleration component. b) Both points have the same instantaneous angular velocity. c) Both points have the same tangential acceleration component. d) Each second, point A turns through a greater angle than point B. e) The angular velocity at point A is greater than that of point B.

10.5.2. Two points are located on a rigid wheel that is rotating with a decreasing angular velocity about a fixed axis. Point A is located on the rim of the wheel and point B is halfway between the rim and the axis. Which one of the following statements is true concerning this situation? a) Both points have the same radial acceleration component. b) Both points have the same instantaneous angular velocity. c) Both points have the same tangential acceleration component. d) Each second, point A turns through a greater angle than point B. e) The angular velocity at point A is greater than that of point B.

10. 5. 3. As an object rotates, its angular speed increases with time 10.5.3. As an object rotates, its angular speed increases with time. Complete the following statement: The total acceleration of the object is given by a) the vector sum of the angular velocity and the tangential acceleration component divided by the elapsed time. b) the vector sum of the radial acceleration component and the tangential acceleration component. c) the angular acceleration. d) the radial acceleration component. e) the tangential acceleration component.

10. 5. 3. As an object rotates, its angular speed increases with time 10.5.3. As an object rotates, its angular speed increases with time. Complete the following statement: The total acceleration of the object is given by a) the vector sum of the angular velocity and the tangential acceleration component divided by the elapsed time. b) the vector sum of the radial acceleration component and the tangential acceleration component. c) the angular acceleration. d) the radial acceleration component. e) the tangential acceleration component.

10.5.4. Which one of the following statements correctly relates the radial acceleration component and the angular velocity? a) The radial acceleration component is the product of the radius and the square of the angular velocity. b) The radial acceleration component is the square of the angular velocity divided by the radius. c) The radial acceleration component is the product of the radius and the angular velocity. d) The radial acceleration component is the angular velocity divided by the radius. e) The radial acceleration component is independent of the angular velocity.

10.5.4. Which one of the following statements correctly relates the radial acceleration component and the angular velocity? a) The radial acceleration component is the product of the radius and the square of the angular velocity. b) The radial acceleration component is the square of the angular velocity divided by the radius. c) The radial acceleration component is the product of the radius and the angular velocity. d) The radial acceleration component is the angular velocity divided by the radius. e) The radial acceleration component is independent of the angular velocity.

10.6.1. An object is rolling, so its motion involves both rotation and translation. Which one of the following statements must be true concerning this situation? a) The total mechanical energy is equal to the sum of the translational kinetic energy and the gravitational potential energy of the object. b) The translational kinetic energy may be equal to zero joules. c) The gravitational potential energy must be changing as the object rolls. d) The rotational kinetic energy must be constant as the object rolls. e) The total mechanical energy is equal to the sum of the translational and rotational kinetic energies and the gravitational potential energy of the object.

10.6.1. An object is rolling, so its motion involves both rotation and translation. Which one of the following statements must be true concerning this situation? a) The total mechanical energy is equal to the sum of the translational kinetic energy and the gravitational potential energy of the object. b) The translational kinetic energy may be equal to zero joules. c) The gravitational potential energy must be changing as the object rolls. d) The rotational kinetic energy must be constant as the object rolls. e) The total mechanical energy is equal to the sum of the translational and rotational kinetic energies and the gravitational potential energy of the object.

10.6.2. Which one of the following statements provides the best definition of rotational inertia? a) Rotational inertia is the momentum of a rotating object. b) Rotational inertia is the same as the mass of a rotating object. c) Rotational inertia is the resistance of an object to a change in its angular velocity. d) Rotational inertia is the resistance of an object to a change in its linear velocity. e) Rotational inertia is the resistance of an object to a change in its angular acceleration.

10.6.2. Which one of the following statements provides the best definition of rotational inertia? a) Rotational inertia is the momentum of a rotating object. b) Rotational inertia is the same as the mass of a rotating object. c) Rotational inertia is the resistance of an object to a change in its angular velocity. d) Rotational inertia is the resistance of an object to a change in its linear velocity. e) Rotational inertia is the resistance of an object to a change in its angular acceleration.

10.7.1. A flat disk, a solid sphere, and a hollow sphere each have the same mass m and radius r. The three objects are arranged so that an axis of rotation passes through the center of each object. The rotation axis is perpendicular to the plane of the flat disk. Which of the three objects has the largest rotational inertia? a) The solid sphere and hollow sphere have the same rotational inertia and it is the largest. b) The hollow sphere has the largest rotational inertia. c) The solid sphere has the largest rotational inertia. d) The flat disk has the largest rotational inertia. e) The flat disk and hollow sphere have the same rotational inertia and it is the largest.

10.7.1. A flat disk, a solid sphere, and a hollow sphere each have the same mass m and radius r. The three objects are arranged so that an axis of rotation passes through the center of each object. The rotation axis is perpendicular to the plane of the flat disk. Which of the three objects has the largest rotational inertia? a) The solid sphere and hollow sphere have the same rotational inertia and it is the largest. b) The hollow sphere has the largest rotational inertia. c) The solid sphere has the largest rotational inertia. d) The flat disk has the largest rotational inertia. e) The flat disk and hollow sphere have the same rotational inertia and it is the largest.

10.7.2. Which one of the following statements concerning the rotational inertia is false? a) The rotational inertia depends on the angular acceleration of the object as it rotates. b) The rotational inertia may be expressed in units of kg • m2. c) The rotational inertia depends on the orientation of the rotation axis relative to the particles that make up the object. d) Of the particles that make up an object, the particle with the smallest mass may contribute the greatest amount to the rotational inertia. e) The rotational inertia depends on the location of the rotation axis relative to the particles that make up the object.

10.7.2. Which one of the following statements concerning the rotational inertia is false? a) The rotational inertia depends on the angular acceleration of the object as it rotates. b) The rotational inertia may be expressed in units of kg • m2. c) The rotational inertia depends on the orientation of the rotation axis relative to the particles that make up the object. d) Of the particles that make up an object, the particle with the smallest mass may contribute the greatest amount to the rotational inertia. e) The rotational inertia depends on the location of the rotation axis relative to the particles that make up the object.

10.7.3. Two solid spheres have the same mass, but one is made from lead and the other from pine wood. How do the rotational inertias of the two spheres compare? a) The rotational inertia of the lead sphere is greater than that of the one made of wood. b) The rotational inertia of the wood sphere is greater than that of the one made of lead. c) The rotational inertia of the wood sphere is the same as that of the one made of lead. d) There is no way to compare the spheres without knowing their radii.

10.7.3. Two solid spheres have the same mass, but one is made from lead and the other from pine wood. How do the rotational inertias of the two spheres compare? a) The rotational inertia of the lead sphere is greater than that of the one made of wood. b) The rotational inertia of the wood sphere is greater than that of the one made of lead. c) The rotational inertia of the wood sphere is the same as that of the one made of lead. d) There is no way to compare the spheres without knowing their radii.

10.7.4. The parallel-axis theorem is used in the calculation of which of the following parameters? a) angular acceleration b) torque c) angular velocity d) rotational inertia e) radial acceleration

10.7.4. The parallel-axis theorem is used in the calculation of which of the following parameters? a) angular acceleration b) torque c) angular velocity d) rotational inertia e) radial acceleration

10.8.1. An object, which is considered a rigid body, is not in equilibrium. Which one of the following expressions must be true concerning the angular acceleration  and translational acceleration a of the object? a)  = 0 rad/s2 and a = 0 m/s2 b)  > 0 rad/s2 and a = 0 m/s2 c) a > 0 m/s2 and  = 0 rad/s2 d)  > 0 rad/s2 and a > 0 m/s2 e) Either  > 0 rad/s2 or a > 0 m/s2.

10.8.1. An object, which is considered a rigid body, is not in equilibrium. Which one of the following expressions must be true concerning the angular acceleration  and translational acceleration a of the object? a)  = 0 rad/s2 and a = 0 m/s2 b)  > 0 rad/s2 and a = 0 m/s2 c) a > 0 m/s2 and  = 0 rad/s2 d)  > 0 rad/s2 and a > 0 m/s2 e) Either  > 0 rad/s2 or a > 0 m/s2.

10.8.2. The units of torque are which of the following? a) newtons (N) b) N  m c) kg/s2 d) kg  m2 e) angular newtons

10.8.2. The units of torque are which of the following? a) newtons (N) b) N  m c) kg/s2 d) kg  m2 e) angular newtons

10.9.1. Complete the following statement: When determining the net torque on a rigid body, only the torques due to a) internal forces are considered. b) external forces are considered. c) forces that are either parallel or perpendicular to the lever arms are considered. d) forces that form action-reaction pairs, as in applying Newton’s third law of motion, are considered. e) internal and external forces are considered.

10.9.1. Complete the following statement: When determining the net torque on a rigid body, only the torques due to a) internal forces are considered. b) external forces are considered. c) forces that are either parallel or perpendicular to the lever arms are considered. d) forces that form action-reaction pairs, as in applying Newton’s third law of motion, are considered. e) internal and external forces are considered.