The acceleration of the $2\,kg$ block if the free end of the string is pulled with a force of $20\,N$ as shown in the figure is:

$A$ lift is tied with thick iron ropes having mass $M$. The maximum acceleration of the lift is $a \ m/s^2$ and the maximum safe stress is $S \ N/m^2$. The minimum diameter of the rope is

$A$ painter is applying force himself to raise him and the box with an acceleration of $5\, m/s^2$ by a massless rope and pulley arrangement as shown in the figure. The mass of the painter is $100\, kg$ and that of the box is $50\, kg$. If $g = 10\, m/s^2$,then:

In the case of a wire having negligible mass,suspended from a ceiling and stretched under the action of a weight $F$ suspended from its other end,the tension at any cross-section of the wire is

$A$ 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 ........... $N$.

Three blocks of masses $4\,kg$,$6\,kg$ and $8\,kg$ are hanging over a fixed pulley as shown. The tension in the string connecting the $8\,kg$ and $4\,kg$ blocks is: