Consider a car moving along a straight horizontal road with a speed of $72\, km/h$. If the coefficient of kinetic friction between the tyres and the road is $0.5,$ the shortest distance in which the car can be stopped is ........ $m$ .$[g = 10\,m{s^{ - 2}}]$
$30$
$40$
$72$
$20$
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 ........ $m/{s^2}$
Consider a car moving on a straight road with a speed of $100\, m/s$. The distance at which car can be stopped, is ........ $m$. $[\mu_k = 0.5]$
The limiting friction is
An insect crawls up a hemispherical surface very slowly. The coefficient of friction between the insect and the surface is $1/3$. If the line joining the centre of the hemispherical surface to the insect makes an angle $\alpha $ with the vertical, the maximum possible value of $\alpha $ so that the insect does not slip is given by