A uniform plank of Young’s modulus $Y $ is moved over a smooth horizontal surface by a constant horizontal force $F.$ The area of cross section of the plank is $A.$ The compressive strain on the plank in the direction of the force is

The modulus of elasticity is dimensionally equivalent to

A block of weight $100 N$ is suspended by copper and steel wires of same cross sectional area $0.5 cm ^2$ and, length $\sqrt{3} m$ and $1 m$, respectively. Their other ends are fixed on a ceiling as shown in figure. The angles subtended by copper and steel wires with ceiling are $30^{\circ}$ and $60^{\circ}$, respectively. If elongation in copper wire is $\left(\Delta \ell_{ C }\right)$ and elongation in steel wire is $\left(\Delta \ell_{ s }\right)$, then the ratio $\frac{\Delta \ell_{ C }}{\Delta \ell_{ S }}$ is. . . . . .

[Young's modulus for copper and steel are $1 \times 10^{11} N / m ^2$ and $2 \times 10^{11} N / m ^2$ respectively]

Young's modulus depends upon

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 ?

With rise in temperature, the Young's modulus of elasticity