A force $f$ is acting on a block of mass $m$. Coefficient of friction between block and surface is $\mu$. The block can be pulled along the surface if :-
$\tan \theta \ge \mu $
$\cot \theta \ge \mu $
$\tan \frac{\theta }{2} \ge \mu $
$\cot \frac{\theta }{2} \ge \mu $
A horizontal force of $10 \,N$ is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is $0.2$. the weight of the block is ........ $N$
A circular racetrack of radius $300\; m$ is banked at an angle of $15^o$. If the coefficient of friction between the wheels of a race-car and the road is $0.2$, what is the
$(a)$ optimum speed of the racecar to avoid wear and tear on its tyres, and
$(b)$ maximum permissible speed to avoid slipping ?
When a bicycle is in motion, the force of friction exerted by the ground on the two wheels is such that it acts
Write unit of coefficient of static friction.
A cyclist speeding at $18 \;km/h$ on a level road takes a sharp circular turn of radius $3\; m$ without reducing the speed. The co-efficient of static friction between the tyres and the road is $0.1$. Will the cyclist slip while taking the turn?