A dentists drill starts from rest After 250 s of constant an

A dentist\'s drill starts from rest. After 2.50 s of constant angular acceleration it turns at a rate of 2.10 10⁴ rev/min.

(a) Find the drill\'s angular acceleration.
1 rad/s²
(b) Determine the angle (in radians) through which the drill rotates during this period.
2 rad

Solution

a)

angular acceleration,

A = v/t

where v = final angular speed = 2.1*10^4 rev/min

= (2.1*10^4*2*pi/60) rad/s

= 2199 rad/s

So,

A = 2199/2.5 = 879.6 rad/s2 <------answer

b)

angle rotated, s = 0.5*A*t^2

= 0.5*879.6*2.5^2

= 2748.75 rad <-----answer