## College Physics (4th Edition)

Let $\alpha$ be the angular acceleration. $a_t = \alpha ~r~~$ is the tangential acceleration. Since $\alpha$ is constant, then $a_t$ is also constant. The tangential acceleration component is constant. $a_c = \omega^2~r~~$ is the radial acceleration. Because there is an angular acceleration, the value of $\omega$ will change. Therefore, the radial acceleration component is not constant.