1. A small solid sphere and a small thin hoop are rolling along a horizontal surface with the same translational speed when they encounter a 20° rising slope. If these two objects roll up the slope without slipping, which will rise farther up the slope?
(a) The sphere.
(b) The hoop.
(c) Both the same.
(d) More information about the objects' mass and diameter is needed.
2. A small mass m on a string is rotating without friction in a circle. The string is shortened by pulling it through the axis of rotation without any external torque, Fig. 8-39. What happens to the angular velocity of the object?
(a) It increases.
(b) It decreases.
(c) It remains the same.