Three blocks are placed as shown in figure. Mass of $A, B$ and $C$ are $m_1, m_2$ and $m_3$ respectively. The force exerted by block$\text{'}C\text{'}$ on $\text{'}B\text{'}$ is

The value of $\frac{T_3}{T_1}$ is

A block of mass $10 \mathrm{kg}$ is moving on a rough surface as shown in figure. The frictional force acting on block is

Block of mass $10 \mathrm{kg}$ is moving on inclined plane with constant velocity $10 \mathrm{m} {\mathrm{s}}^{-1}.$ The coefficient of kinetic friction between incline plane and block is

The ratio of acceleration of blocks $A$ placed on smooth incline with block $B$ placed on rough incline is $2: 1.$ The coefficient of kinetic friction between block $B$ and incline is

A block of mass $10 \mathrm{kg}$ is released on rough incline plane. Block start descending with acceleration $2 \mathrm{m} {\mathrm{s}}^{-2}.$ Kinetic friction force acting on block is $\left(\mathrm{take} \mathrm{g}=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$

A block of mass $10 \mathrm{kg}$ is kept on a fixed rough $(\mu =0.8)$ inclined plane of angle of inclination $30°.$ The frictional force acting on the block is