#### Answer

(a) $\omega$ is positive and $\alpha$ is positive.
(b) $\omega$ is negative and $\alpha$ is positive.
(c) $\omega$ is positive and $\alpha$ is negative.
(d) $\omega$ is negative and $\alpha$ is negative.

#### Work Step by Step

$\omega$ is positive when the object is rotating counterclockwise. $\omega$ is negative when the object is rotating clockwise.
$\alpha$ is positive when the angular acceleration is counterclockwise. $\alpha$ is negative when the angular acceleration is clockwise.
(a) $\omega$ is positive and $\alpha$ is positive.
(b) $\omega$ is negative and $\alpha$ is positive.
(c) $\omega$ is positive and $\alpha$ is negative.
(d) $\omega$ is negative and $\alpha$ is negative.