The angular acceleration of the body in terms of the angular velocity is,
[tex]\alpha=\frac{\text{angular velocity}}{\text{time}}[/tex]The angular velocity in terms of the linear velocity is,
[tex]\text{angular velocity=}\frac{v}{r}[/tex]where v is the linear velocity and r is the radius,
Thus, the angular acceleration becomes,
[tex]\begin{gathered} \alpha=\frac{1}{r}\times\frac{v}{t} \\ \alpha=\frac{a}{r} \end{gathered}[/tex]where a is the linear acceleration of the body,