Figure shows an arrangement of blocks, pulley and strings. Strings and pulley are massless and frictionless. The relation between acceleration of the blocks as shown in the figure is

In the figure shown, two blocks of masses $2 \mathrm{kg}$ and $4 \mathrm{kg}$ are connected by a massless string which is just taut ($i.e.,$ tension is zero at this moment). Now two forces $4 \mathrm{N}$ and $15 \mathrm{N}$ are applied on blocks. The tension in the string is (coefficient of static and kinetic friction are same). $\left[g=10 \mathrm{m} {\mathrm{s}}^{-2}\right]$

A block of mass $m$ is kept on a plank. The coefficient of friction between the plank and block is $1.$The plank is slowly raised from one end so that it makes angle $\theta$ with horizontal. The forces of friction acting on the plank, when $\theta =30°$ and $\theta =60°$are respectively,

A force of $100 \mathrm{N}$ is applied on a block of mass $3 \mathrm{kg}$, as shown in the figure. The coefficient of friction between the surface and the block is $\frac{1}{4}$. The frictional force acting on the block, to keep it at rest, is

A block of mass $5 \mathrm{kg}$ is placed on a rough horizontal plane. The coefficients of static and kinetic friction between the block and surface are $0.5$ and $0.3$ respectively. A force of $100 \mathrm{N}$ is applied at an angle $30°$ with the horizontal as shown in the figure. The acceleration of the block will be $\left[g=10 \mathrm{m} {\mathrm{s}}^{-2}\right]$

In the given figure the co-efficient of friction between the block and the incline plane is $\text{'}1\text{'}.$ The acceleration with which the system should be accelerated so that the friction between the block and the wedge becomes zero $\left(g=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$ is

A force of $49 \mathrm{N}$ is just able to move a block of wood weighing $10 \mathrm{kg}$on a rough horizontal surface, then coefficient of friction is

Find the compression in the spring if the system shown below is in equilibrium.