Ten one-rupee coins are placed on top of each other on a table. Each coin has mass $m$. The reaction force of the $6^{th}$ coin (counted from the bottom) on the $7^{th}$ coin is .......... $mg$.

$A$ cord is used to lower vertically a block of mass $M$ by a distance $d$ with constant downward acceleration $\frac{g}{4}$. Work done by the cord on the block is

Two blocks of masses $2m$ and $m$ are placed on a smooth horizontal surface. $A$ force $F$ is applied on the $2m$ block towards the right,and the same force $F$ is applied on the $m$ block towards the left. What is the ratio of the contact forces between the two blocks in the two cases?

Two blocks,each having mass $M$,rest on frictionless surfaces as shown in the figure. If the pulleys are light and frictionless,and $M$ on the incline is allowed to move down,then the tension in the string will be

$A$ rope of length $10 \, m$ and linear density $0.5 \, kg/m$ is lying lengthwise on a smooth horizontal floor. It is pulled by a force of $25 \, N$. The tension in the rope at a point $8 \, m$ away from the point of application is ....... $N$

Two masses of $5 \,kg$ and $3 \,kg$ are suspended with the help of massless inextensible strings as shown in the figure below. When the whole system is moving upwards with an acceleration of $2 \,m/s^2$, the value of $T_1$ is (use $g = 9.8 \,m/s^2$): (in $\,N$)