Hooke's law is applicable for ....

The elastic limit for a gas

Why does strain have no unit?

The load versus elongation graph for four wires of same length and the same material is shown in the figure. The thinnest wire is represented by the line:

The two thigh bones (femurs),each of cross-sectional area $10 \, cm^2$,support the upper part of a person of mass $50 \, kg$. The average pressure sustained by the femurs is ............. $N/m^2$.

$A$ composite heavy rope made of two materials is suspended vertically from a high ceiling. The ratios of different quantities for the upper rope to the lower rope are: length $\frac{L_u}{L_l} = \frac{1}{2}$,cross-sectional area $\frac{A_u}{A_l} = \frac{2}{1}$,and density $\frac{d_u}{d_l} = \frac{2}{3}$. What is the ratio of the maximum stress in the two ropes?