$A$ body is moving along a rough horizontal surface with an initial velocity $6\,m/s$. If the body comes to rest after travelling $9\,m$,then the coefficient of sliding friction will be

$A$ block of mass $m=2 \ kg$ is initially at rest on a horizontal surface. $A$ horizontal force $F_1=(6 \ N) \hat{i}$ and a vertical force $F_2=(10 \ N) \hat{j}$ are then applied to the block. The coefficients of static friction and kinetic friction for the block and the surface are $0.4$ and $0.25$,respectively. The magnitude of the frictional force acting on the block is (assume $g=10 \ m/s^2$): (in $N$)

What is kinetic friction? What is rolling friction?

$A$ block of mass $10 \, kg$ moving with an acceleration of $2 \, m/s^2$ on a horizontal rough surface is shown in the figure. The value of the coefficient of kinetic friction is ...........

The blocks shown in the figure move with a constant velocity of $10 \, m/s$ towards the right. All surfaces in contact are rough. The friction force applied by the ground on block $B$ is ........ $N$.

$A$ car is moving on a straight horizontal road with a speed $v.$ If the coefficient of friction between the tyres and the road is $\mu ,$ the shortest distance in which the car can be stopped is