The number of revolutions that the disk made may be calculate by the equation,
2 x a x d = (Vf)² - (V1)²
where a is the acceleration. Vf and V1 are the final and initial velocities, respectively. Substituting the known values,
2 x (190 rad/s²) x (1 rev / 2π rad)x (60 sec/ 1 min)² x d = (7200 rpm)² - 0
The value of d is approximately equal to 238.1 revolutions.
