일반물리학 1 — Rotation: Problem 34

34 Figure 10-23 gives angular speed versus time for a thin rod that rotates around one end. The scale on the \(\omega\) axis is set by \(\omega_s = 6.0 \text{ rad/s}\). (a) What is the magnitude of the rod’s angular acceleration? (b) At \(t = 4.0 \text{ s}\), the rod has a rotational kinetic energy of \(1.60 \text{ J}\). What is its kinetic energy at \(t = 0\)?