A uniform metal chain of mass $m$ and length ' $L$ ' passes over a massless and frictionless pulley. It is released from rest with a part of its length ' $l$ ' is hanging on one side and rest of its length ' $L -l$ ' is hanging on the other side of the pulley. At a certain point of time, when $l=\frac{L}{x}$, the acceleration of the chain is $\frac{g}{2}$. The value of $x$ is ........
$6$
$2$
$1.5$
$4$
The boxes of masses $2\, {kg}$ and $8\, {kg}$ are connected by a massless string passing over smooth pulleys. Calculate the time taken by box of mass $8\; {kg}$ to strike the ground starting from rest. (use $\left.{g}=10\, {m} / {s}^{2}\right)$ (in ${s}$)
Figure shows a boy on a horizontal platform $A$ on a smooth horizontal surface, holding a rope attached to a box $B$ . Boy pulls the rope with a constant force of $50\ N$ . (boy does not slip over the platform). The combined mass of platform $A$ and boy is $250\ kg$ and that of box $B$ is $500\ kg$ . The velocity of $A$ relative to the box $B$ , $5\ s$ after the boy on $A$ begins to pull the rope, will be ............ $m/s$
Find the velocity of the hanging block if the velocities of the free ends of the rope are as indicated in the figure.
In the figure shown the velocity of different blocks is shown. The velocity of $C$ is $.........\,m/s$
A block of mass $M$ is tied to one end of massless rope. The other end of rope is in the hands of a man of mass $2M$ as show in figure. Initially the block and the man are resting on a rough plank of mass $2M$ as shown in figure. The whole system is resting on a smooth horizontal surface. The man pulls the rope. Pulley is massless and frictionless. What is the magnitude of displacement of the plank when the block meets the pulley ......... $m $ (Man does not leave his position on the plank during the pull).