The spring balance does not read properly after its long use,because

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 ............. $N/m^2$.

Distinguish between a rigid body and a solid body.

Under the elastic limit,the stress is:

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

$A$ rod of constant cross-section moves towards the right with constant acceleration $a$. The graph of stress versus distance from the left end is shown in the figure. If the density of the material of the rod at cross-section $1$ is $9 \text{ g/cm}^3$,find the density at cross-section $2$ in $\text{g/cm}^3$.