$A$ student takes $50 \, g$ of wax (specific heat $= 0.6 \, cal/g \cdot ^\circ C$) and heats it until it boils. The graph between temperature and time is shown below. The heat supplied to the wax per minute and the boiling point are respectively:

$A$ boy is able to chew $20 \, g$ of ice cream in $5 \, minutes$. Calculate the power of the boy in horse power $(HP)$. (Assume the latent heat of fusion of ice is $80 \, cal/g$ and $1 \, cal = 4.2 \, J$).

$A$ $10.0 \,W$ electrical heater is used to heat a container filled with $0.5 \,kg$ of water. It is found that the temperature of the water and the container rose by $3 \,K$ in $15 \,min$. The container is then emptied,dried,and filled with $2 \,kg$ of an oil. It is now observed that the same heater raises the temperature of the container-oil system by $2 \,K$ in $20 \,min$. Assuming no other heat losses in any of the processes,the specific heat capacity of the oil is ................ $\times 10^3 \,J K^{-1} kg^{-1}$.

Work done in converting $1 \, g$ of ice at $-10^{\circ} C$ into steam at $100^{\circ} C$ is .......... $kJ$.

$A$ lead bullet moving with velocity $V$ strikes a wall and stops. If $75 \%$ of its energy is converted into heat,then the increase in temperature is ($s=$ specific heat of lead,$J=$ mechanical equivalent of heat).

Why is cooking faster in a pressure cooker?