Physics

Problem

The angular velocity

\omega

of a rotor varies with time as follows (units are rad/s): •

0\le t<2\,\text{s}:\; \omega=+3

•

2\le t<5\,\text{s}:\; \omega=-2

•

5\le t<7\,\text{s}:\; \omega=0

•

7\le t<9\,\text{s}:\; \omega=+1

If counter-clockwise rotation is defined as positive, during which interval is the rotor rotating clockwise? a)

0\,\text{s to }2\,\text{s}

2\,\text{s to }5\,\text{s}

5\,\text{s to }7\,\text{s}

7\,\text{s to }9\,\text{s}