Given : $\sigma$ is the compressibility of water, $\rho$ is the density of water and $K$ is the bulk modulus of water. What is the energy density of water at the bottom of a lake $‘h’$ metre deep ?
$\frac{1}{2}\sigma {(h\rho g)^2}$
$\frac{1}{2}\sigma {(h\rho g)}$
$\frac{1}{2}\frac{{h\rho g}}{\sigma }$
$\frac{{h\rho g}}{\sigma }$
Does the energy stored in a spring changes when it stretched or compressed ?
Two wires of the same material (Young's modulus $Y$ ) and same length $L$ but radii $R$ and $2R$ respectively are joined end to end and a weight $W$ is suspended from the combination as shown in the figure. The elastic potential energy in the system is
When a $4\, kg$ mass is hung vertically on a light spring that obeys Hooke's law, the spring stretches by $2\, cms$. The work required to be done by an external agent in stretching this spring by $5\, cms$ will be ......... $joule$ $(g = 9.8\,metres/se{c^2})$
Identical springs of steel and copper are equally stretched. On which more work will have to be done ?
An Indian rubber cord $L$ metre long and area of cross-section $A$ $metr{e^2}$ is suspended vertically. Density of rubber is $D$ $kg/metr{e^3}$ and Young's modulus of rubber is $E$ $newton/metr{e^2}$. If the wire extends by $l$ metre under its own weight, then extension $l$ is