A lead bullet at $27\,^oC$ just melts when stopped by an obstacle. Assuming that $25\%$ of heat is absorbed by the obstacle, then the velocity of the bullet at the time of striking is …….. $m/s$ ($M.P.$ of lead $= 327\,^oC,$ specific heat of lead $= 0.03\,cal/g\,^oC,$ latent heat of  fusion of lead $= 6\,cal/g$ and $J = 4.2\,joule/cal$ )

$2\,g$ of steam condenses when passed through $40\,g$ of water initially at $25\,^oC$. The condensation of steam raises the temperature of water to $54.3\,^oC$, …….. $cal/g$ is the  latent heat of steam ?

A small quantity, mass $m$ , of water at a temperature $\theta $ (in $^oC$ ) is poured on to a large mass $M$ of ice which is at its melting point. If $c$ is the specific heat of water and $L$ the latent heat of fusion of ice, then the mass of ice melted is given by

A steel tape measures the length of a copper rod as $90\, cm$ when both are at $10\,^oC$. …….. $cm$ would the tape read for the length of rod when both are at $30\,^oC$ ? $[\alpha _{st} = 1.2\times10^{-5}/^oC$ and $\alpha _{cu} = 1.7\times10^{-5}/^oC]$

If mass-energy equivalence is taken into account, when water is cooled to from ice. The mass of water should