posted by Matthew .
An electric motor rotating a workshop grind- ing wheel at a rate of 147 rev/min is switched off with a constant deceleration of 1.24 rad/s2.
How long does it take for the grinding wheel to stop?
Answer in units of s
Through how many radians has the wheel turned during the deceleration?
Answer in units of rad
change rev/min to rev/second
then, wf=wi+at where a=-1.24r/s^2
solve for t.
Dfinal(in radians)=wi*t+1/2 a t^2