Three blocks, $A, B$ and $C,$ of masses $4\,kg, 2\,kg$ and $1\,kg$ respectively, are in contact on a frictionless surface, as shown. If a force of $14\,\,N$ is applied on the $4\,\,kg$  block, then the contact force between $A$ and $B$  is ....... $N$

A wedge of height $H$ (fixed) and inclination $\alpha $ (variable) is moving on a smooth horizontal surface with constant acceleration $g\ m/s^2$ . A small block is placed at bottom of incline as shown in figure, slips on the smooth surface of incline . Choose $CORRECT$ statement about time taken by block to reach the top of incline

A block of mass $M$ is at rest on a plane surface inclined at an angle $\theta$ to the horizontal. The magnitude of force exerted by the plane on the block is

Arrangement of two block system is as shown. The net force acting on $1 \,kg$ and $2 \,kg$ blocks are (assuming the surfaces to be frictionless) respectively

$Assertion$ : A man and a block rest on smooth horizontal surface. The man holds a rope which is connected to block. The man cannot move on the horizontal surface

$Reason$ : A man standing at rest on smooth horizontal surface cannot start walking due to absence of friction (The man is only in contact with floor as shown).

A wooden wedge of mass $M$ and inclination angle $(\alpha)$ rest on a smooth floor. A block of mass $m$ is kept on wedge. A force $F$ is applied on the wedge as shown in the figure such that block remains stationary with respect to wedge. So, magnitude of force $F$ is