A fireman tosses his 0.98-kg hat onto a peg, where it oscillates as a physical pendulum (FIGURE

Question:

A fireman tosses his 0.98-kg hat onto a peg, where it oscillates as a physical pendulum (FIGURE 13-37). If the center of mass of the hat is 8.4 cm from the pivot point, and its period of oscillation is 0.73 s, what is the moment of inertia of the hat about the pivot point?