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

Three blocks $A, B$ and $C $ weighing $1, 8$ and $27\, kg$ respectively are connected as shown in the figure with an inextensible string and are moving on a smooth surface. ${T_3}$ is equal to $36\, N$. Then ${T_2}$ is ........ $N$

A block of mass $m$ is placed on a smooth inclined wedge $ABC$ of  inclination $\theta$ as shown in the figure. The wedge is given an acceleration $a$ towards the right. The relation between $a$ and $\theta$ for the block to remain stationary on the wedge is

Figure shows two blocks connected by a light inextensible string as shown in figure. A force of $10 \,N$ is applied on the bigger block at $60^{\circ}$ with horizontal, then the tension in the string connecting the two masses is ....... $N$

In the figure shown $'P'$ is a plate on which a wedge $B$ is placed and on $B$ a block $A$ of mass $m$ is placed. The plate is suddenly removed and system of $B$ and $A$ is allowed to fall under gravity. Neglecting any force due to air on $A$ and $B$, the normal force on $A$ due to $B$ is

Two blocks are connected by a string as shown in the diagram. The upper block is hung by another string. A force $F$ applied on the upper string produces an acceleration of $2\,m/{s^2}$ in the upward direction in both the blocks. If $T$ and $T'$ be the tensions in the two parts of the string, then $T$ and $T'$