Physic
posted by Anthony on .
An electric motor rotating a workshop grinding wheel at a rate of 114 rev/min is switched off. Assume the wheel has a constant negative angular acceleration of magnitude 2.10 rad/s2.
(a) How long does it take for the grinding wheel to stop?

wf=0=wi+2at
0=114*2PI/60 + 2(2.10)t
solve for time, t 
6.09