Physics

Problem

The angular velocity of a rotating disc decreases uniformly from

20\,\text{rad s}^{-1}

4\,\text{rad s}^{-1}

4\,\text{s}

. What is its angular acceleration during this interval? a)

+4\,\text{rad s}^{-2}

-5\,\text{rad s}^{-2}

-4\,\text{rad s}^{-2}

+6\,\text{rad s}^{-2}