One end of a string of length $l$ is connected to a particle of mass $m$ and the other to a small peg on a smooth horizontal table. If the particle moves in a circle with speed $v$,the net force on the particle (directed towards the centre) is ($T$ is the tension in the string).

Three blocks $M_1, M_2, M_3$ having masses $4 \ kg, 6 \ kg$ and $10 \ kg$ respectively are hanging from a smooth pulley using ropes $1, 2$ and $3$ as shown in the figure. The tension in the rope $1, T_1$,when they are moving upward with an acceleration of $2 \ m/s^2$ is ............... $N$ (if $g = 10 \ m/s^2$).

$A$ uniform rope of mass $M$ and length $L$ is fixed at its upper end vertically from a rigid support. The tension in the rope at a distance $l$ from the rigid support is:

$A$ 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 $1\,s$.

In the system shown in the figure,the pulleys and strings are ideal. Find the acceleration of $m_1$ with respect to $m_2$ $(m_1 = 2\ kg, m_2 = 2\ kg)$.

Two blocks $A$ and $B$,each of the same mass,are attached by a thin inextensible string through an ideal pulley. Initially,block $B$ is held in position as shown in the figure. Now,block $B$ is released. Block $A$ will slide to the right and hit the pulley in time $t_A$. Block $B$ will swing and hit the surface in time $t_B$. Assume the surface is frictionless. [Hint: Tension $T$ in the string acting on both blocks is the same in magnitude. Acceleration needed for horizontal motion is provided by $T$.]