Density of rubber is $d$. $ A$ thick rubber cord of length $L$ and cross-section area $A$ undergoes elongation under its own weight on suspending it. This elongation is proportional to
$dL$
$Ad/L$
$Ad/{L^2}$
$d{L^2}$
A uniformly tapering conical wire is made from a material of Young's modulus $Y$ and has a normal, unextended length $L.$ The radii, at the upper and lower ends of this conical wire, have values $R$ and $3R,$ respectively. The upper end of the wire is fixed to a rigid support and a mass $M$ is suspended from its lower end. The equilibrium extended length, of this wire, would equal
The force required to stretch a steel wire of $1\,c{m^2}$ cross-section to $1.1$ times its length would be $(Y = 2 \times {10^{11}}\,N{m^{ - 2}})$
A metallic rod having area of cross section $A$, Young’s modulus $Y$, coefficient of linear expansion $\alpha $ and length $L$ tied with two strong pillars. If the rod is heated through a temperature $t\,^oC$ then how much force is produced in rod ?
A rod of length $L$ at room temperature and uniform area of cross section $A$, is made of a metal having coefficient of linear expansion $\alpha {/^o}C$. It is observed that an external compressive force $F$, is applied on each of its ends, prevents any change in the length of the rod, when it temperature rises by $\Delta \,TK$. Young’s modulus, $Y$, for this metal is
A boy’s catapult is made of rubber cord which is $42\, cm$ long, with $6\, mm$ diameter of cross -section and of negligible mass. The boy keeps a stone weighing $0.02\, kg$ on it and stretches the cord by $20\, cm$ by applying a constant force. When released, the stone flies off with a velocity of $20\, ms^{-1}$. Neglect the change in the area of cross section of the cord while stretched. The Young’s modulus of rubber is closest to