Two identical weights of mass $M$ are linked by a thread wrapped around a frictionless pulley with a fixed axis. $A$ small weight of mass $m$ is placed on one of the weights. What is the reaction force between $m$ and $M$?

Two masses of $1\, kg$ and $5\, kg$ are attached to the ends of a massless string passing over a pulley of negligible weight. The pulley itself is attached to a light spring balance as shown in the figure. When the masses are released and start moving,the reading of the spring balance will be:

In the arrangement shown in the figure, the work done by the string on the block of mass $0.36 \,kg$ during the first second after the blocks are released from a state of rest is: (Ignore friction and the mass of the string.)
(Acceleration due to gravity, $g = 10 \,m/s^2$) (in $\,J$)

Two blocks of mass $M$ and $m$ are kept on a trolley of mass $M_0$ as shown in the figure. All surfaces are smooth. Select the correct statement.

$A$ 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 $l$ hanging on one side and the rest of its length $L - l$ hanging on the other side of the pulley. At a certain point in time,when $l = \frac{L}{x}$,the acceleration of the chain is $\frac{g}{2}$. The value of $x$ is ........

$A$ uniform chain of length $2L$ is hanging in equilibrium over a small,smooth pulley. If end $B$ is given a slightly downward displacement $x$,the imbalance causes an acceleration. The acceleration of the chain when it has been displaced by distance $x$ is: