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 ......... $N$

......... $m/s^2$ is magnitude of acceleration of a block moving with speed $10\,m/s$ on a rough surface if coefficient of friction is $0.2$.

A chain of length $L$ rests on a rough table. If $\mu $ be the coefficient of friction, the maximum friction of the chain that can hang over the table will be

A $1.0 kg$ block of wood sits on top of an identical block of wood, which sits on top of a flat level table made of plastic. The coefficient of static friction between the wood surfaces is $\mu_1$, and the coefficient of static friction between the wood and plastic is $\mu_2$. Ahorizontal force $F$ is applied to the top block only, and this force is increased until the top block starts to move. The bottom block will move with the top block if and only if

A block of weight $W$ is kept on a rough horizontal surface (friction coefficient $\mu$). Two forces $W/2$ each are applied as shown in the figure. Choose the $CORRECT$ statement :-

In the figure shown, horizontal force $F_1$ is applied on a block but the block does not slide. Then as the magnitude of vertical force $F_2$ is increased from zero the block begins to slide; the correct statement is