A child weighing $25 \,kg$ slides down a rope hanging from a branch of a tall tree. If the force of friction acting against him is $200 \,N$, the acceleration of child is ........... $m / s^2$ $\left(g=10 \,m / s ^2\right)$

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 particle is projected with a speed ${v_0} = \sqrt {gR} $ . The coefficient of friction between the particle and the hemispherical plane is $\mu  = 0.5$ . Then, the initial acceleration of the particle is

Consider a car moving on a straight road with a speed of $100\, m/s$. The distance at which car can be stopped, is ........ $m$. $[\mu_k = 0.5]$

A block slides down on incline of angle $30^o$ with an acceleration $\frac{g}{4}$. Find the coefficient of kinetic friction

A car having a mass of $1000\, kg$ is moving at a speed of $30\, metres/sec$. Brakes are applied to bring the car to rest. If the frictional force between the tyres and the road surface is $5000$ newtons, the car will come to rest in ........ $\sec$