Someone is using a scissors to cut a wire of circular cross section and negligible weight. The wire slides in the direction away from the hinge until the angle between the scissors blades becomes $2 \alpha$. The friction coefficient between the blades and the wire, is :-
$\sqrt {1-tan \alpha}$
$2cos \alpha$
$tan \alpha$
$2\, tan \alpha$
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 block is stationary on a rough inclined plane. How many forces are acting on the block?
In the figure, a block of weight $60\, N$ is placed on a rough surface. The coefficient of friction between the block and the surfaces is $0.5$. ........ $N$ should be the maximum weight $W$ such that the block does not slip on the surface .
A block pressed against the vertical wall is in equilibrium. The minimum coefficient of friction is:-
A block of mass $M$ is held against a rough vertical well by pressing it with a finger. If the coefficient of friction between the block and the wall is $\mu $ and acceleration due to gravity is $g$, calculate the minimum force required to be applied by the finger to hold the block against the wall.