The ideal mechanical advantage of the combination of pulleys shown is

$A$ block of mass $M$ is pulled along a horizontal frictionless surface by a rope of mass $M/2$. If a force $2Mg$ is applied at one end of the rope,the force which the rope exerts on the block is -

$A$ man uses two pulleys to raise himself with an acceleration of $2\,m/s^2$,as shown in the figure. The man stands on a light weighing machine fitted on a horizontal platform. Determine the reading of the weighing machine. (Mass of man $= 75\,kg$,mass of platform $= 25\,kg$,$g = 10\,m/s^2$) (in $,N$)

An arrangement of a spring,strings,a pulley,and masses is shown in the figure below. The pulley and the strings are massless and $M > m$. The spring is light with spring constant $k$. If the string connecting $m$ to the ground is detached,then immediately after detachment,

In the system shown in the figure,there is no friction anywhere. The block $C$ $(2 \, kg)$ moves down by a distance $x_0 = 10 \, cm$ with respect to the wedge $D$ $(4 \, kg)$ when the system is released from rest. The velocity of $A$ $(1 \, kg)$ with respect to $B$ $(1 \, kg)$ will be $(g = 10 \, m/s^2)$ ......... $m/s$.

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).