A uniform rope lies on a horizontal table so that a part of it hangs over the edge. The rope begins to slide down when the length of the hanging part is $25\%$ of the entire length. The coefficient of friction between the rope and the table is

A marble block of mass $2\, kg$ lying on ice when given a velocity of $6\, m/s$ is stopped by friction in $10s$. Then the coefficient of friction is-

A body of mass $\mathrm{m}$ is kept on a rough horizontal surface (coefficient of friction $=\mu$ ) A horizontal force is applied on the body, but it does not move. The resultant of normal reaction and the frictional force acting on the object is given by $\mathrm{F},$ where $\mathrm{F}$ is

Write advantages and disadvantages of friction. Write remedies to reduce friction.

A body of mass m rests on horizontal surface. The coefficient of friction between the body and the surface is $\mu .$ If the mass is pulled by a force $P$ as shown in the figure, the limiting friction between body and surface will be

A boy of mass $4\, kg$ is standing on a piece of wood having mass $5 \,kg$. If the coefficient of friction between the wood and the floor is $0.5,$ the maximum force that the boy can exert on the rope so that the piece of wood does not move from its place is ......$N.$(Round off to the Nearest Integer) [Take $g=10 \,ms ^{-2}$ ]