A heavy uniform chain lies on a horizontal table. If the coefficient of friction between the chain and the table is $0.25$ then the maximum fraction of the length of the chain that can hang over one edge of the table is 

A block $A$ with mass $100 \mathrm{kg}$ is resting on another block $B$ of mass $200 \mathrm{kg}$. As shown in figure, a horizontal rope tied to a wall holds it. The coefficient of friction between $A$ and $B$ is $0.2$ while the coefficient of friction between $B$ and the ground is $0.3$. The minimum required force $F$ to start moving $B$ will be,

A block of mass $2 \mathrm{kg}$ is kept on the floor. The coefficient of static friction is $0.4$. If a force $F$ of $2.5 \mathrm{N}$ is applied on the block as shown in the figure, the frictional force between the block and the floor will be,

Given in the figure are two blocks $A$ and $B$ of weights $20 \mathrm{N}$ and $100 \mathrm{N}$, respectively. These are being pressed against a wall by a force $F$ as shown. If the coefficient of friction between the blocks is $0.1$ and between block $B$ and the wall is $0.15$, the frictional force applied by the wall on block $B$ is,

A block of mass $m$ is lying on a horizontal surface of coefficient of friction $\mathrm{\mu }$. A force is applied to the block at an angle $\mathrm{\theta }$ with the horizontal. The block will move with a minimum force $F$ if,

A block of mass $M=5 \mathrm{kg}$ is resting on a rough horizontal surface for which the coefficient of friction is $0.2$. When a force $F=40 \mathrm{N}$ is applied, the acceleration of the block will be $\left(g=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$, 

A body of mass $20 \mathrm{kg}$ is moving on a rough horizontal plane. A block of mass $3 \mathrm{kg}$ is connected to the $20 \mathrm{kg}$ mass by a string of negligible mass through a smooth pulley as shown in the figure. The tension in the string is $27 \mathrm{N}$. The coefficient of kinetic friction between the heavier mass and the surface $\left(g=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$ is,