Question 1

A single force acts on a particle situated on the positive x axis. The torque about the origin is in the negative z direction. The force might be:

Accepted Answer

A)  in the positive y direction 
B)  in the negative y direction 
C)  in the positive x direction 
D)  in the negative x direction 
E)  in the positive z direction 
A)  in the positive y direction 
B)  in the negative y direction 
C)  in the positive x direction 
D)  in the negative x direction 
E)  in the positive z direction

Question 2

A cylinder of radius R = 6.0 cm is on a rough horizontal surface. The coefficient of kinetic friction between the cylinder and the surface is 0.30 and the rotational inertia for rotation about the axis is given by MR2/2, where M is its mass. Initially it is not rotating but its center of mass has a speed of 7.0 m/s. After 2.0 s the speed of its center of mass and its angular velocity about its center of mass, respectively, are:

Accepted Answer

A)  1.1 m/s, 0 
B)  1.1 m/s, 19 rad/s 
C)  1.1 m/s, 98 rad/s 
D)  1.1 m/s, 200 rad/s 
E)  5.9 m/s, 98 rad/s 
A)  1.1 m/s, 0 
B)  1.1 m/s, 19 rad/s 
C)  1.1 m/s, 98 rad/s 
D)  1.1 m/s, 200 rad/s 
E)  5.9 m/s, 98 rad/s

Question 3

The fundamental dimensions of angular momentum are:

Accepted Answer

A)  mass·length·time-1 
B)  mass·length-2·time-2 
C)  mass·2·time-1 
D)  mass·length2·time-2 
E)  none of these 
A)  mass·length·time-1 
B)  mass·length-2·time-2 
C)  mass·2·time-1 
D)  mass·length2·time-2 
E)  none of these

Question 4

A block with mass M, on the end of a string, moves in a circle on a horizontal frictionless table as shown. As the string is slowly pulled through a small hole in the table:

Accepted Answer

A)  the angular momentum of M remains constant 
B)  the angular momentum of M decreases 
C)  the kinetic energy of M remains constant 
D)  the kinetic energy of M decreases 
E)  none of the above 
A)  the angular momentum of M remains constant 
B)  the angular momentum of M decreases 
C)  the kinetic energy of M remains constant 
D)  the kinetic energy of M decreases 
E)  none of the above

Question 5

A forward force acting on the axle accelerates a rolling wheel on a horizontal surface. If the wheel does not slide the frictional force of the surface on the wheel is:

Accepted Answer

A)  zero 
B)  in the forward direction and does zero work on the wheel 
C)  in the forward direction and does positive work on the wheel 
D)  in the backward direction and does zero work on the wheel 
E)  in the backward direction and does positive work on the wheel 
A)  zero 
B)  in the forward direction and does zero work on the wheel 
C)  in the forward direction and does positive work on the wheel 
D)  in the backward direction and does zero work on the wheel 
E)  in the backward direction and does positive work on the wheel

Question 6

A 6.0-kg particle moves to the right at 4.0 m/s as shown. The magnitude of its angular momentum about the point O is:

Accepted Answer

A)  zero 
B)  288 kg . m2/s 
C)  144 kg . m2/s 
D)  24 kg.m2/s 
E)  249 kg.m2/s 
A)  zero 
B)  288 kg . m2/s 
C)  144 kg . m2/s 
D)  24 kg.m2/s 
E)  249 kg.m2/s

Question 7

A solid wheel with mass M, radius R, and rotational inertia MR2/2, rolls without sliding on a horizontial surface. A horizontal force F is applied to the axle and the center of mass has an acceleration a. The magnitudes of the applied force F and the frictional force f of the surface, respectively, are:

Accepted Answer

A)  F = Ma, f = 0 
B)  F = Ma, f = Ma/2 
C)  F = 2Ma, f = Ma 
D)  F = 2Ma, f = Ma/2 
E)  F = 3Ma/2, f = Ma/2 
A)  F = Ma, f = 0 
B)  F = Ma, f = Ma/2 
C)  F = 2Ma, f = Ma 
D)  F = 2Ma, f = Ma/2 
E)  F = 3Ma/2, f = Ma/2

Question 8

A phonograph record is dropped onto a freely spinning turntable. Then:

Accepted Answer

A)  neither angular momentum nor mechanical energy is conserved because of the frictional forces between record and turntable 
B)  the frictional force between record and turntable increases the total angular momentum 
C)  the frictional force between record and turntable decreases the total angular momentum 
D)  the total angular momentum remains constant 
E)  the sum of the angular momentum and rotational kinetic energy remains constant 
A)  neither angular momentum nor mechanical energy is conserved because of the frictional forces between record and turntable 
B)  the frictional force between record and turntable increases the total angular momentum 
C)  the frictional force between record and turntable decreases the total angular momentum 
D)  the total angular momentum remains constant 
E)  the sum of the angular momentum and rotational kinetic energy remains constant

Question 9

As a 2.0-kg block travels around a 0.50-m radius circle it has an angular speed of 12 rad/s. The circle is parallel to the xy plane and is centered on the z axis, 0.75 m from the origin. The magnitude of its angular momentum around the origin is:

Accepted Answer

A)  6.0 kg . m2/s 
B)  9.0 kg . m2/s 
C)  11 kg . m2/s 
D)  14 kg . m2/s 
E)  20 kg . m2/s 
A)  6.0 kg . m2/s 
B)  9.0 kg . m2/s 
C)  11 kg . m2/s 
D)  14 kg . m2/s 
E)  20 kg . m2/s

Question 10

A rod rests on frictionless ice. Forces that are equal in magnitude and opposite in direction are simultaneously applied to its ends as shown. The quantity that vanishes is its:

Accepted Answer

A)  angular momentum 
B)  angular acceleration 
C)  total linear momentum 
D)  kinetic energy 
E)  rotational inertia 
A)  angular momentum 
B)  angular acceleration 
C)  total linear momentum 
D)  kinetic energy 
E)  rotational inertia

Question 11

A pulley with radius R and rotational inertia I is free to rotate on a horizontal fixed axis through its center. A string passes over the pulley. A block of mass m1 is attached to one end and a block of mass m2, is attached to the other. At one time the block with mass m1 is moving downward with speed v. If the string does not slip on the pulley, the magnitude of the total angular momentum, about the pulley center, of the blocks and pulley, considered as a system, is given by:

Accepted Answer

A)  (m1 - m2)vR + Iv/R 
B)  (m1 + m2)vR + Iv/R 
C)  (m1 - m2)vR - Iv/R 
D)  (m1 + m2)vR - Iv/R 
E)  none of the above 
A)  (m1 - m2)vR + Iv/R 
B)  (m1 + m2)vR + Iv/R 
C)  (m1 - m2)vR - Iv/R 
D)  (m1 + m2)vR - Iv/R 
E)  none of the above

Question 12

A single force acts on a particle P. Rank each of the orientations of the force shown below according to the magnitude of the time rate of change of the particle's angular momentum about the point O, least to greatest.

Accepted Answer

A)  1, 2, 3, 4 
B)  1 and 2 tie, then 3, 4 
C)  1 and 2 tie, then 4, 3 
D)  1 and 2 tie, then 3 and 4 tie 
E)  All are the same 
A)  1, 2, 3, 4 
B)  1 and 2 tie, then 3, 4 
C)  1 and 2 tie, then 4, 3 
D)  1 and 2 tie, then 3 and 4 tie 
E)  All are the same

Question 13

As a 2.0-kg block travels around a 0.50-m radius circle with an angular speed of 12 rad/s. The circle is parallel to the xy plane and is centered on the z axis, 0.75 m from the origin. The component in the xy plane of the angular momentum around the origin has magnitude:

Accepted Answer

A)  0 
B)  6.0 kg . m2/s 
C)  9.0 kg. m2/s 
D)  11 kg .m2/s 
E)  14 kg .m2/s 
A)  0 
B)  6.0 kg . m2/s 
C)  9.0 kg. m2/s 
D)  11 kg .m2/s 
E)  14 kg .m2/s

Question 14

The coefficient of static friction between a certain cylinder and a horizontal floor is 0.40. If the rotational inertia of the cylinder about its symmetry axis is given by I = (1/2)MR2, then the maximum acceleration the cylinder can have without sliding is:

Accepted Answer

A)  0.1 g 
B)  0.2 g 
C)  0.4 g 
D)  0.8 g 
E)  g 
A)  0.1 g 
B)  0.2 g 
C)  0.4 g 
D)  0.8 g 
E)  g

Exam 11: Rolling, Torque, and Angular Momentum

A single force acts on a particle situated on the positive x axis. The torque about the origin is in the negative z direction. The force might be:

The fundamental dimensions of angular momentum are:

A block with mass M, on the end of a string, moves in a circle on a horizontal frictionless table as shown. As the string is slowly pulled through a small hole in the table:

A forward force acting on the axle accelerates a rolling wheel on a horizontal surface. If the wheel does not slide the frictional force of the surface on the wheel is:

A 6.0-kg particle moves to the right at 4.0 m/s as shown. The magnitude of its angular momentum about the point O is:

A phonograph record is dropped onto a freely spinning turntable. Then:

As a 2.0-kg block travels around a 0.50-m radius circle it has an angular speed of 12 rad/s. The circle is parallel to the xy plane and is centered on the z axis, 0.75 m from the origin. The magnitude of its angular momentum around the origin is:

A rod rests on frictionless ice. Forces that are equal in magnitude and opposite in direction are simultaneously applied to its ends as shown. The quantity that vanishes is its:

A single force acts on a particle P. Rank each of the orientations of the force shown below according to the magnitude of the time rate of change of the particle's angular momentum about the point O, least to greatest.

As a 2.0-kg block travels around a 0.50-m radius circle with an angular speed of 12 rad/s. The circle is parallel to the xy plane and is centered on the z axis, 0.75 m from the origin. The component in the xy plane of the angular momentum around the origin has magnitude:

The coefficient of static friction between a certain cylinder and a horizontal floor is 0.40. If the rotational inertia of the cylinder about its symmetry axis is given by I = (1/2)MR2, then the maximum acceleration the cylinder can have without sliding is:

Measurement

Motion Along a Straight Line

Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Equilibrium and Elasticity

Gravitation

Fluids

Oscillations

Waves I

Waves II

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Electric Charge

Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference

Diffraction

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

The coefficient of static friction between a certain cylinder and a horizontal floor is 0.40. If the rotational inertia of the cylinder about its symmetry axis is given by I = (1/2)MR², then the maximum acceleration the cylinder can have without sliding is: