Exam 8: Rotational Motion

A triatomic molecule is oriented as follows along the x -axis: mass m is at the origin, mass 2 m is at x=a , and, mass 3 m is at x=2 a . What is the moment of inertia of this molecule about the y -axis?

Two equal-magnitude forces are applied to a door at the doorknob. The first force is applied perpendicular to the door, and the second force is applied at 30° to the plane of the door. Which Force exerts the greater torque about the door hinge?

Suppose a solid uniform sphere of mass M and radius R rolls without slipping down an inclined plane starting from rest. The angular velocity of the sphere at the bottom of the incline depends on

The rotating systems shown in the figure differ only in that the two identical movable masses are positioned a distance r from the axis of rotation (left), or a distance $r / 2$ from the axis of rotation (right). If you release the hanging blocks simultaneously from rest,

A uniform ball with diameter of 10 cm rolls without slipping on a horizontal tabletop. The moment of inertia of the ball about an axis through its center is $2.2 \times 10 ^ { - 3 } \mathrm {~kg} \cdot \mathrm { m } ^ { 2 }$ translational speed of its center is 0.45 m/s. (a) What is its angular speed of the ball about its center of mass? (b) What is the rotational kinetic energy of the ball? (c) What is the ball's angular momentum about its center of mass?

What is the kinetic energy of a 120-cm thin uniform rod with a mass of 450 g that is rotating about its center at 3.60 rad/s?

A spinning ice skater on extremely smooth ice is able to control the rate at which she rotates by pulling in her arms. Which of the following statements are true about the skater during this Process? (There could be more than one correct choice.)

A turntable 45 cm in diameter starts from rest and makes its first complete revolution in 3.4 s with constant angular acceleration. If it maintains the same acceleration, how long will it take the turntable to make its second complete revolution?