$A$ 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

The figure shows three blocks in contact and kept on a smooth horizontal surface. What is the ratio of the force exerted by block $A$ on $B$ to that of $B$ on $C$?

$A$ small block of mass $m$ is placed on a wedge of mass $M$ as shown, which is initially at rest. All surfaces are frictionless. The spring attached to the other end of the wedge has a force constant $k$. If $a'$ is the acceleration of $m$ relative to the wedge as it starts sliding down and $A$ is the acceleration acquired by the wedge, then the maximum velocity of $M$ is:

$A$ small block of mass $m$ is placed on a wedge of mass $M$ as shown,which is initially at rest. All the surfaces are frictionless. The spring attached to the other end of the wedge has a force constant $k$. If $a'$ is the acceleration of $m$ relative to the wedge as it starts coming down and $A$ is the acceleration acquired by the wedge as the block starts coming down,then the maximum retardation of $M$ is:

$A$ freely falling body has attained a velocity of $2 \,m/s$. If the weight of the body is now opposed by a constant upward air resistance force equal to its weight, what is the total distance travelled by the body before it comes to rest (in $\,m$)?

$A$ block $A$ of mass $7 \, kg$ is placed on a frictionless table. $A$ thread tied to it passes over a frictionless pulley and carries a body $B$ of mass $3 \, kg$ at the other end. The acceleration of the system is .......... $m \, s^{-2}$ (given $g = 10 \, m \, s^{-2}$).