At what value of $m_1$ will the $8\, kg$ mass be at rest?

Objects $A$ and $B$,each of mass $m$,are connected by a light inextensible cord. They are constrained to move on a frictionless ring in a vertical plane as shown in the figure. The objects are released from rest at the positions shown. The tension in the cord just after release will be

$A$ pendulum bob of mass $50 \,g$ is suspended from the ceiling of an elevator. The tension in the string if the elevator goes up with uniform velocity is approximately .......... $N$.

Given $m_1 = 4m_2$. The acceleration of $m_1$ is $a$. The time taken for $m_1$ to reach the ground is ........ $\text{sec}$. (Assume the initial height is $0.2 \text{ m}$)

Two masses $M_{1}$ and $M_{2}$ are tied together at the two ends of a light inextensible string that passes over a frictionless pulley. When the mass $M_{2}$ is twice that of $M_{1}$,the acceleration of the system is $a_{1}$. When the mass $M_{2}$ is thrice that of $M_{1}$,the acceleration of the system is $a_{2}$. The ratio $\frac{a_{1}}{a_{2}}$ will be:

$A$ mass $M$ is lowered by the help of a string at a constant acceleration of $\frac{g}{2}$ for a distance $x$. What is the work done by the string?