A solid cylinder of mass m and radius R has a string wound around it. A person holding the string pulls it vertically upward, as shown, such that the cylinder is suspended in midair for a brief time interval Δt and its center of mass does not move. The tension in the string is T, and the rotational inertia of the cylinder about its axis is ½ MR2.
1. The net force on the cylinder during the time interval Δt is
A: T-mgR
B: mgR-T
C: mg
D: zero
The linear acceleration of the person's hand during the time interval Δt is
A: 2g
B: T/m-g
C: T/m
D: g/2