Q.

A solid circular disc of mass 50 kg rolls along a horizontal floor so that its center of mass has a speed of 0.4 m/s. The absolute value of work done on the disc to stop it is ______ J.                  [2024]


Ans.

(6)     Using work energy theorem

         W=ΔKE=0-(12mv2+12Iω2)

         W=0-12mv2(1+K2R2)

         =-12×50×0.42(1+12)=-6J

         Absolute work=+6J

         W=-6J    |W|=6J