The increase in length is $l$ of a wire of length $L$ by the longitudinal stress. Then the stress is proportional to

$A$ lift of mass $1600 \text{ kg}$ is supported by a thick iron wire. If the maximum stress which the wire can withstand is $4 \times 10^8 \text{ N/m}^2$ and its radius is $4 \text{ mm}$,then the maximum acceleration the lift can take is . . . . . . $\text{m/s}^2$. (Take $g = 10 \text{ m/s}^2$ and $\pi = 3.14$)

If the length of a string is $P$ when the tension in it is $6 \ N$ and its length is $Q$ when the tension in it is $8 \ N$,then the original length of the string is

What is elasticity? What is an elastic body?

One end of a uniform rod of mass $m_1$ and cross-sectional area $A$ is hung from a ceiling. The other end of the rod is supporting a mass $m_2$. The stress at the midpoint of the rod is:

The elastic limit for a gas