$A$ car of mass $1000\,kg$ is moving at a speed of $30\,m/s.$ Brakes are applied to bring the car to rest. If the net retarding force is $5000\,N,$ the car comes to stop after travelling $d\,m$ in $t\,s.$ Then

In the diagram shown,the normal reaction force between the $2\,kg$ and $1\,kg$ blocks is (Consider the surface to be smooth) $.........N$ (Given $g = 10\,ms^{-2}$)

Consider two masses $m_1$ and $m_2$ connected through a pulley as shown in the figure. Mass $m_2$ starts from rest at height $h$ and falls down. With what speed does it hit the ground? (Assume no friction and massless strings and pulleys.)

Two masses $M$ and $m$ are connected by a weightless string. They are pulled by a force $F$ on a frictionless horizontal surface as shown in the figure. The tension in the string will be

An elevator accelerates upwards at a constant rate. $A$ uniform string of length $L$ and mass $m$ supports a small block of mass $M$ that hangs from the ceiling of the elevator. The tension at distance $l$ from the ceiling is $T$. The acceleration of the elevator is

$A$ trolley of mass $20 \ kg$ is attached to a block of mass $4 \ kg$ by a massless string passing over a frictionless pulley as shown in the figure. If the coefficient of kinetic friction between the trolley and the surface is $0.02$,then the acceleration of the trolley and block system is (take $g=10 \ ms^{-2}$):- (in $ms^{-2}$)