Two blocks of masses $m$ and $M$ are connected by means of a metal wire of cross-sectional area $A$ passing over a frictionless fixed pulley as shown in the figure. The system is then released. If $M = 2m$,then the stress produced in the wire is

One end of a light string is fixed to a clamp on the ground and the other end passes over a fixed frictionless pulley as shown in the figure. It makes an angle of $30^{\circ}$ with the ground. The clamp can tolerate a vertical force of $40 \,N$. If a monkey of mass $5 \,kg$ were to climb up the rope,then the maximum acceleration in the upward direction with which it can climb safely is $\left(g=10 \,ms^{-2}\right)$ (in $\,ms^{-2}$)

$A$ smooth massless string passes over a smooth fixed pulley. Two masses $m_{1}$ and $m_{2}$ $(m_{1} > m_{2})$ are tied at the two ends of the string. The masses are allowed to move under gravity starting from rest. The total external force acting on the two masses is

An inextensible string passing over a smooth pulley connects two blocks of masses $m_1$ and $m_2$ $(m_2 > m_1)$ vertically. If the acceleration of the system is $(\frac{g}{n})$, then the ratio of masses $(\frac{m_2}{m_1})$ is

$A$ block of mass $25 \; kg$ is raised by a $50 \; kg$ man in two different ways as shown in the figure. What is the action on the floor by the man in the two cases? If the floor yields to a normal force of $700 \; N$,which mode should the man adopt to lift the block without the floor yielding?

Three blocks $A, B$ and $C$ are suspended as shown in the figure. The mass of each block $A$ and $C$ is $m$. If the system is in equilibrium and the mass of $B$ is $M$,then: