• # question_answer In the figure the block of mass m is at rest on the floor. The acceleration with which a monkey of mass m should climb up along the rope of negligible mass so as to lift the block from the floor is: A)  $=\left( \frac{M}{m}-1 \right)g$      B)  $>\left( \frac{M}{m}-1 \right)g$C)  $\frac{M}{m}g$                            D)  $>\frac{M}{m}g$

Equation of motion for M, Since M is stationary             $T-Mg=0$                 $T=Mg$                             ?.(i) Since, the monkey moves up with an acceleration a             $T-mg=ma$                 $T-m(g+a)$                      ?..(ii) Equating equations (i) and (ii), we obtain             $Mg=m(g+a)$                 $a=\left( \frac{M}{m}-1 \right)g$ That means, if $a>\left( \frac{M}{m}-1 \right)g,$ the block M can be lifted from the floor.