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 masses $M =100\,kg , m _{1}=10\,kg$ and $m_{2}=20\,kg$ are arranged in a system as shown in figure. All the surfaces are frictionless and strings are inextensible and weightless. The pulleys are also weightless and frictionless. $A$ force $F$ is applied on the system so that the mass $m_{2}$ moves upward with an acceleration of $2\,ms ^{-2}$. The value of $F$ is $......N$

$\left(\right.$ Take $\left.g =10\,ms ^{-2}\right)$

Two blocks of mass $M$ and $m$ are kept on the trolley whose all surfaces are smooth select the correct statement

What force should be applied on the wedge so that block over it does not move? (All surfaces are smooth)

Three blocks with masses $m, 2m $ and $3 m$ are connected by strings, as shown in the figure. After an upward force $F$ is applied on block $m,$ the masses move upward at constant speed $v.$ What is the net force on the block of mass $2\ m\ ?\, (g$ is the acceleration due to gravity$)$

A horizontal force $10 \mathrm{~N}$ is applied to a block $A$ as shown in figure. The mass of blocks $A$ and $B$ are $2 \mathrm{~kg}$ and $3 \mathrm{~kg}$ respectively. The blocks slide over a frictionless surface. The force exerted by block $A$ on block $B$ is :