A body takes $1\frac{1}{3}$ times as much time to slide down a rough identical but smooth inclined plane. If the angle of inclined plane is $45^o$, the coefficient of friction is

A block of mass $10\, kg$ moving at $10\,m/s$ is released to slide on rough surface having  coefficient of friction $0.2.$ It will stop by travelling distance ........ $m$

The coefficient of static friction between a wooden block of mass $0.5\, kg$ and a vertical rough wall is $0.2$ The magnitude of horizontal force that should be applied on the block to keep it adhere to the wall will be $N$ $\left[ g =10\, ms ^{-2}\right]$

Why are mountain roads generally made winding upwards rather than going straight up ?

A uniform rod of length $L$ and mass $M$ has been placed on a rough horizontal surface. The horizontal force $F$ applied on the rod is such that the rod is just in the state of rest. If the coefficient of friction varies according to the relation $\mu = Kx$ where $K$ is a $+$ ve constant. Then the tension at mid point of rod is

If mass of $A = 10\,\,kg$, coefficient of static friction $= 0.2$, coefficient of kinetic friction = $0.2$. Then mass of $B$ to start motion is