When we rub our palms,they get heated,but only up to a maximum temperature because:

$A$ block of mass $5\, kg$ is kept on a rough horizontal floor. It is given a velocity $33\, m/s$ towards the right. $A$ force of $20\sqrt{2}\, N$ continuously acts on the block as shown in the figure. If the coefficient of friction between the block and the floor is $0.5$, the velocity of the block after $3\, seconds$ is ........ $m/s$ $(g = 10\, m/s^2)$.

$A$ body is travelling with $10 \,ms^{-1}$ on a rough horizontal surface. Its velocity after $2 \,s$ is $4 \,ms^{-1}$. The coefficient of kinetic friction between the block and the plane is (acceleration due to gravity $= 10 \,ms^{-2}$)

$A$ stone weighing $1$ kg and sliding on ice with a velocity of $2$ m/s is stopped by friction in $10$ sec. The force of friction (assuming it to be constant) will be ......... $N$.

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

$A$ body of weight $64 \ N$ is pushed with just enough force to start it moving across a horizontal floor and the same force continues to act afterwards. If the coefficients of static and dynamic friction are $0.8$ and $0.6$ respectively,then the acceleration of the body will be