An old-style elevator is connected to a counterweight by a cable that passes over a rotating disk 2.50 m in diameter as shown in the figure. The elevator is raised and lowered by turning the disk, and the cable does not slip on the rim of the disk but turns with it. Starting from rest, the elevator is raised at a constant rate of 1.225 m/s2. (a) What must be the angular acceleration of the disk? At the instant that the elevator reaches a height of 3.25 m, what is (b) the angular speed of the disk, (c) the radial acceleration at a point on the rim of the disk and (d) through how many revolutions has the disk turned?

An old-style elevator is connected to a counterweight by a cable that passes over a rotating disk 2.50 m in diameter as shown in the figure. The elevator is raised and lowered by turning the disk, and the cable does not slip on the rim of the disk but turns with it. Starting from rest, the elevator is raised at a constant rate of 1.225 m/s2. (a) What must be the angular acceleration of the disk? At the instant that the elevator reaches a height of 3.25 m, what is (b) the angular speed of the disk, (c) the radial acceleration at a point on the rim of the disk and (d) through how many revolutions has the disk turned?