A computer hard disk starts from rest, then speeds up with an angular acceleration of 190 rad/s2 until it reaches its final angular speed of 7200 rpm.How many revolutions has the disk made 10.0 s after it starts up?
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.
