A constant torque is acting on a wheel. If starting from rest, the wheel makes n rotations in t seconds, Show that the angular acceleration is given by
`alpha = \frac { 4 \pi n } { t ^ { 2 } }` rad `s^-2`.

Explanation

Initial angular velocity ` omega_0 = 0`
Number of rotations in t seconds = n
angular displacement ` theta = 2pi n `
but , ` theta = omega_0 t + 1/2 at^2`
` 2pi n = 1/2 at^2`
`alpha = (4pi n)/(t^2)`