Consider a car moving on a straight road with a speed of $100\, m/s$. The distance at which the car can be stopped is ........ $m$. $[\mu_k = 0.5, g = 10\, m/s^2]$

$A$ body of mass $20 \,kg$ is moving on a rough horizontal plane. $A$ block of mass $3 \,kg$ is connected to the $20 \,kg$ mass by a string of negligible mass through a smooth pulley as shown in the figure. The tension in the string is $27 \,N$. The coefficient of kinetic friction between the heavier mass and the surface is $\left(g=10 \,m/s^2\right)$.

$A$ block of mass $40 \,kg$ slides over a surface,when a mass of $4 \,kg$ is suspended through an inextensible massless string passing over a frictionless pulley as shown below. The coefficient of kinetic friction between the surface and the block is $0.02$. The acceleration of the block is ............ $m/s^2$. (Given $g = 10 \,m/s^2$.)

$A$ particle of mass '$m$' at rest on a rough horizontal surface with a coefficient of friction '$\mu$' is given a velocity '$u$'. The average power imparted by friction before it stops is:

$A$ body is travelling with $10 \,ms^{-1}$ on a rough horizontal surface. Its velocity after $2 \,s$ is $4 \,ms^{-1}$. The coefficient of kinetic friction between the block and the plane is (acceleration due to gravity $= 10 \,ms^{-2}$)

$A$ body of mass $2 \, kg$ is kept by pressing it against a vertical wall by a force of $100 \, N$. The coefficient of friction between the wall and the body is $0.3$. Then the frictional force is equal to ........ $N$.