A block of mass $m$ is placed on a surface with a vertical cross section given by $y = \frac{{{x^3}}}{6}$ If the coefficient of friction is $0.5$,the maximum height above the ground at which the block can be placed without slipping is:

A block of mass $M$ placed on rough surface of coefficient of friction equal to $3$ . If $F$ is the $(4/5)$ of the minimum force required to just move. Find out the force exerted by ground on the block

Put a uniform meter scale horizontally on your extended index fingers with the left one at $0.00 cm$ and the right one at $90.00 cm$. When you attempt to move both the fingers slowly towards the center, initially only the left finger slips with respect to the scale and the right finger does not. After some distance, the left finger stops and the right one starts slipping. Then the right finger stops at a distance $x_R$ from the center ( $50.00 cm$ ) of the scale and the left one starts slipping again. This happens because of the difference in the frictional forces on the two fingers. If the coefficients of static and dynamic friction between the fingers and the scale are $0.40$ and $0.32$ , respectively, the value of $x_R($ in $cm )$ is. . . . . . . 

A block of mass $10 \,kg$. moving with acceleration $2 \,m / s ^2$ on horizontal rough surface is shown in figure The value of coefficient of kinetic friction is ...........

A $60\, kg$ body is pushed with just enough force to start it moving across a floor and the same force continues to act afterwards. The coefficient of static friction and sliding friction are $0.5$ and $0.4$ respectively. The acceleration of the body is  ........ $m/{s^2}$

Explain dynamic friction. Write laws of kinetic friction. Define coefficient of kinetic friction.