$A$ 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

$A$ 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 $g = 10 \, m \, s^{-2}$).

$A$ block of mass $48 \ kg$ kept on a smooth horizontal surface is pulled by a rope of length $4 \ m$ by a horizontal force of $25 \ N$ applied to the other end. If the linear density of the rope is $0.5 \ kg \ m^{-1}$,the force acting on the block is (in $N$)

$A$ steel block of $10\, \text{kg}$ rests on a horizontal floor. When three iron cylinders,each of mass $20\, \text{kg}$,are placed on it as shown,the entire system (block + cylinders) moves downward with an acceleration of $0.2\, \text{m/s}^2$. The normal reaction $R$ exerted by the floor is ..... $\text{N}$. [Take $g = 10\, \text{m/s}^2$]

$A$ block of mass $M$ is pulled along a horizontal frictionless surface by a rope of mass $m$. If a force $P$ is applied at the free end of the rope,the force exerted by the rope on the block will be

An elevator of mass $m$ is connected to a rope which pulls the elevator up with a maximum acceleration equal to $a$. If the maximum bearable tension in the rope is $T$,then for a safe journey the minimum diameter of the rope is $[g=$ acceleration due to gravity$]$