Rotation Quiz

A disk of radius 0.5 m rotates about a center axle. The angular position as a function of time for a point on the edge of the disk is shown. Which of the following quantities can be correctly mathematically determined from the graph? Select all correct answers.

In each of the pulleys shown below, the mass of the pulleys is the same in each case as are their radii. In one case, the pulley is shaped like a disk, in another a ring with two light (massless) spindles and a third with massive rope wound inside the pulley as shown. Mass of the disk = Mass of the ring = Mass of the ring+massive rope wound inside. Which of the pulley systems has the greatest moment of inertia?

A uniform rod is hinged at the one end (the dark dot on the left). What is the magnitude and direction of the net torque on the rod?

In an experiment, a student applies a net force to the edge of a disk for 10s. The student may change the magnitude and the direction of the force at any time in the experiment. A graph of the net torque exerted on the edge of the disk as a function of time is shown. After observing the graph, the student concludes that the angular momentum of the disk has not changed. Does the graph support the student’s conclusion? Justify your answer.