A solid cylinder of mass 'm' and radius 'R' rests on a plank of mass '2m' lying on a smooth horizontal surface. String connecting the cylinder to the plank is passing over a massless pulley mounted on a movable light block B, and the friction between the cylinder and the plank is sufficient to prevent slipping. If the block B is pulled with a constant force 'F', find the acceleration of the cylinder and that of the plank.
For the cyclinder, F2−f=ma1 ...(i)
Taking moment of forces about C fR=Iα
⇒f=mRα2(∵ I=mR22) .......(ii)
For the plank, F2+f=(2m)a2 ......(iii)
And at the point of contact P, the acceleration of the two bodies must be same
a1−Rα=a2 .....(iv)
from (i)and(ii),(iii)and(iv)F=(ma1+2ma2),andF2+mRα2=2ma2
substititing value of α and solving for a1 and a2, we get acceleration of plank, a2=2F7m,and acceleration
of cyclinder, a1=3F7m