$10\, kg$ block is placed as shown, if $F = 50$ newton find friction force ............ $N$

What is the acceleration of the block and trolley system shown in a Figure, if the coefficient of kinetic friction between the trolley and the surface is $0.04$? What is the tension in the string ? (Take $g = 10\; m s^{-2}$). Neglect the mass of the string.

Consider a block and trolley system as shown in figure. If the coefficient of kinetic friction between the trolley and the surface is $0.04$ , the acceleration of the system in $\mathrm{ms}^{-2}$ is :

(Consider that the string is massless and unstretchable and the pulley is also massless and frictionless):

A block of mass $m$ is placed on a surface with a vertical cross section given by $y = \frac{{{x^3}}}{6}$ If the coefficient of friction is $0.5$,the maximum height above the ground at which the block can be placed without slipping is:

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 ........ $\sec$

A sphere of mass $m$ is set in motion with initial velocity $v_o$ on a surface on which $kx^n$ is the frictional force with $k$ and $n$ as the constants and $x$ as the distance from the point of start. Find the distance in which sphere will stop