# Angular Acceleration

Written by Jerry Ratzlaff on . Posted in Classical Mechanics

Angular acceleration, abbreviated as $$\alpha$$ (Greek symbol alpha), also called rotational acceleration, of an object is the rate at which the angle velocity changes with respect to time.

## Angular Acceleration formulas

 $$\large{ \alpha = \frac { d \omega } { d t } }$$ $$\large{ \alpha = \frac { a_t } { r } }$$ $$\large{ \alpha = \frac { \tau } { I } }$$

### Where:

 Units US SI $$\large{ \alpha }$$  (Greek symbol alpha) = angular acceleration $$\large{\frac{deg}{sec^2}}$$ $$\large{\frac{rad}{sec^2}}$$ $$\large{ d \omega }$$  (Greek symbol omega) = angular velocity differential $$\large{\frac{1}{sec}}$$ $$\large{ a_t }$$ = tangential acceleration $$\large{\frac{deg}{sec^2}}$$ $$\large{\frac{rad}{sec^2}}$$ $$\large{ I }$$ = mass moment of inertia or angular mass $$\large{\frac{lb_f}{ft^2}}$$ $$\large{\frac{kg}{m^2}}$$ $$\large{ r }$$ = radius of circular path $$\large{feet}$$ $$\large{meters}$$ $$\large{ dt }$$ = time differential $$\large{seconds}$$ $$\large{ \tau }$$  (Greek symbol tau) = torque $$\large{lb_f \cdot ft}$$ $$\large{newton \cdot m}$$