Chapter 10, Problem 45PCE

Predict/Explain The minute and hour hands of a clock have a common axis of rotation and equal mass. The minute hand is long thin and uniform; the hour hand is short, thick, and uniform (a) Is the moment of inertia of the minute hand greater than, less than, or equal to the moment of inertia of the hour hand? (b) Choose the best explanation from among the following:

1. I.             The hands have equal mass and hence equal moments of inertia
2. II.          Having mass farther from the axis of rotation results in a greater moment of inertia
3. III.        The more compact hour hand concentrates its mass and has the greater moment of inertia.