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

A block of mass $8\, kg$ is at rest on a rough inclined plane as shown in figure. The magnitude of net force exerted by the surface on the block will be ......... $N$

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  .......... $N$

Two bodies of masses $m_{1}=5\,kg$ and $m _{2}=3\,kg$ are connected by a light string going over a smooth light pulley on a smooth inclined plane as shown in the figure. The system is at rest. The force exerted by the inclined plane on the body of mass $m _{1}$ will be$....N$ [Take $g=10\,ms ^{-2}$ ]

A frictionless cart $A$ of mass $100\  kg$ carries other two frictionless carts $B$ and $C$ having masses $8\  kg$ and $4\  kg$ respectively connected by a string passing over a pulley as shown in the figure. What horizontal force $F$ must be applied on the cart so that smaller cart do not move relative to  it .......... $N$

A block '$A$' takes $2\,s$ to slide down a frictionless incline of $30^{\circ}$ and length ' $l$ ', kept inside a lift going up with uniform velocity ' $v$ '. If the incline is changed to $45^{\circ}$, the time taken by the block, to slide down the incline, will be approximately $........\,s$