$540\  g$ of ice at $0\ ^oC$ is mixed with $540\  g$ water at $80\  ^oC$. The final temperature of the mixture is

$200\, g$ of a solid ball at $20\,^oC$ is dropped in an equal amount of water at $80\,^oC$. The resulting temperature is $60\,^oC$. This means that specific heat of solid is

$2\,kg$ of metal at $100\,^oC$ is cooled by $1\,kg$ of water at $0\,^oC$ . If specific heat capacity of metal is $\frac {1}{2}$ of specific heat capacity of water, final temperature of mixture would be

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 $J = 4.2\,joule/cal$ )

If the earth suddenly stops revolving and all its rotational $KE$ is used up in raising its temperature and if $'s'$ is taken to be the specific heat of the earth's material, the rise of temperature of the earth will be : ( $R -$ radius of the earth and $\omega  =$ its angular velocity, $J =\,Joule$ constant)

A coffee maker makes coffee by passing steam through a mixture of coffee powder, milk and water. If the steam is mixed at the rate of $50 \,g$ per minute in a mug containing $500 \,g$ of mixture, then it takes about $t_0$ seconds to make coffee at $70^{\circ} C$ when the initial temperature of the mixture is $25^{\circ} C$. The value of $t_0$ is close to .......... $s$ (ratio of latent heat of evaporation to specific heat of water is $540^{\circ} C$ and specific heat of the mixture can be taken to be the same as that of water)