What is the tangential acceleration of a point on the surface of the crankshaft?

Question

A 3.00 cm-diameter crankshaft, rotating at 2900 rpm comes to a halt in 1.50 s.

Answer 1

The initial angular velocity is (2900 rev / min) ( 2π radians / rev ) ( 1 min / 60 sec ) = 300 radians / sec.

The angular acceleration α is therefore 300 / 1.5 = 200 radians / s^2

Tangential acceleration a = r α = ( .015 m ) ( 200 radians / s^2 ) = 3 m / s^2