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:

In the figure shown,both blocks are released from rest. Find the time taken for them to cross each other. (Assume $g = 10 \ m/s^2$)

$A$ light string passes over a frictionless pulley. To one of its ends a mass of $6\, kg$ is attached. To its other end a mass of $10\, kg$ is attached. The tension in the thread will be ........ $N$.

$A$ block of mass $M$ is hanging over a smooth and light pulley through a light string. The other end of the string is pulled by a constant force $F$. The kinetic energy of the block increases by $20\,J$ in $1\,s$.

$A$ block of mass $m$ is pulled by a force of $40 \, N$ on a smooth horizontal surface as shown in the figure. The tension at the middle of the block is ........... $N$.

Two masses $m_1 = 5\, kg$ and $m_2 = 4.8\, kg$ tied to a string are hanging over a light frictionless pulley. The acceleration of the masses when they are free to move is $...........\, m/s^2$. $(g = 9.8\, m/s^2)$