The breaking stress of a wire of length $L$ and radius $r$ is $5 \ kg-wt/m^2$. The wire of length $2L$ and radius $2r$ of the same material will have a breaking stress in $kg-wt/m^2$ of:

Two identical solid balls,one of ivory and the other of wet-clay,are dropped from the same height on the floor. Which one will rise to a greater height after striking the floor and why?

In solids,inter-atomic forces are

The length of an elastic string is $a$ metres when the longitudinal tension is $4 \ N$ and $b$ metres when the longitudinal tension is $5 \ N$. The length of the string in metres when the longitudinal tension is $9 \ N$ is

$A$ lift is tied with thick iron ropes having mass $M$. The maximum acceleration of the lift is $a \ m/s^2$ and the maximum safe stress is $s \ N/m^2$. The minimum diameter of the rope is $(g = \text{acceleration due to gravity})$

The shear strain is possible in .............