AP Physics 1

Angular Momentum Example MC

1. What happens to the magnitude of the angular momentum of an object its rotational speed is tripled? a. The angular momentum is nine times as much. b. The angular momentum triples. c. The angular momentum stays the same. d. The angular momentum is one third as much. e. The angular momentum is one ninth as much. 2. What happens to the rotational kinetic energy of an object if its rotational speed is tripled? a. The rotational kinetic energy is nine times as much b. The rotational kinetic energy triples c. The rotational kinetic energy stays the same d. The rotational kinetic energy is one third as much e. The rotational kinetic energy is one ninth as much 3. As an ice skater is spinning, she extends her arms away from her body. Her angular velocity ______, and her angular momentum ______. a. Decrease; increase b. Increase, decrease c. Decrease, decrease d. Remains the same; increase e. Decreases; remains the same 4. A spinning sphere has a moment of inertia of 12 푘푔 ∗ 푚2 and has an angular momentum of 푘푔∗푚2 18 . What is the angular speed of the sphere? 푠 a. 0.67 rad/s b. 1.5 rad/s c. 4 rad/s d. 110 rad/s e. 220 rad/s 5. A cylinder has a moment of inertia, I. How much time does it take torque, τ, to increase its angular speed from 휔1 to 휔2? 퐼휔 − I휔 a. 2 1 휏 휏 b. 퐼휔2− I휔1 휏 c. 1 1 퐼휔2 − 퐼휔2 2 2 2 1 1 1 d. ( 퐼휔2 − 퐼휔2 ) τ 2 2 2 1

6. What is moment of inertia? a. The resistance something has to rotational motion b. The resistance an object has to linear motion c. The integral of volume d. The rotational equivalent of momentum e. The ratio between torque and angular acceleration 7. When a solid object rotates with a constant angular acceleration, which of the following are true? a. The net toque on the object is zero b. The net torque on the object is constant and nonzero c. The net torque on the object must increase d. The object’s angular velocity changes at a steady rate e. The objects angular velocity is constant 8. The moment of inertia of a body does NOT depend on which of the following? a. The angular acceleration of the body b. The distribution of mass in the body c. The angular velocity of the body d. The axis of rotation of the body e. The mass of the body