physics
posted by monic .
A dentist's drill starts from rest. After 2.50 s of constant angular acceleration it turns at a rate of 3.0 104 rev/min.
(a) Find the drill's angular acceleration.
rad/s2
(b) Determine the angle (in radians) through which the drill rotates during this period.
rad

(a) Convert 30,000 rpm to radians per second. Call it w.
w = 52.36 rad/s
Angular acceleration = w/2.5 rad/s^2
(b) Theta = (average angular velocity)*time = (w/2)*2.5 radians.