$A$ stationary object at $4^{\circ}C$ and weighing $3.5\, kg$ falls from a height of $2000\, m$ on a snow mountain at $0^{\circ}C$. If the temperature of the object just before hitting the snow is $0^{\circ}C$ and the object comes to rest immediately $(g = 10\, m/s^2)$ and (latent heat of ice $= 3.5 \times 10^5\, J/kg$),then the amount of ice that will melt is:

$A$ hunter fired a metallic bullet of mass $m \ kg$ from a gun towards an obstacle and it just melts when it is stopped by the obstacle. The initial temperature of the bullet is $300 \ K$. If $\frac{1}{4}$ th of the heat is absorbed by the obstacle,then the minimum velocity of the bullet is (Melting point of bullet $= 600 \ K$,Specific heat of bullet $= 0.03 \ cal \ g^{-1} {}^{\circ} C^{-1}$,Latent heat of fusion of bullet $= 6 \ cal \ g^{-1}$) (in $ms^{-1}$)

Calculate the amount of heat (in calories) required to convert $5\,g$ of ice at $0^{\circ}C$ to steam at $100^{\circ}C$.

What is sublimation? Give names of sublimable substances.

$A$ cylinder of mass $1\,kg$ is given heat of $20000\,J$ at atmospheric pressure. If the initial temperature of the cylinder is $20\,^oC$,then the work done by the cylinder will be .......$J$. (Given: Specific heat of cylinder $= 400\,J\,kg^{-1}\,^oC^{-1}$,Coefficient of volume expansion $= 9 \times 10^{-5}\,^oC^{-1}$,Atmospheric pressure $= 10^5\,N/m^2$,and density of cylinder $= 9000\,kg/m^3$)

Consider two thermometers $T_1$ and $T_2$ of equal length,which can be used to measure temperature over the range $\theta_1$ to $\theta_2$. $T_1$ contains mercury as the thermometric liquid,while $T_2$ contains bromine. The volumes of the two liquids are the same at the temperature $\theta_1$. The volumetric coefficients of expansion of mercury and bromine are $18 \times 10^{-5} \, K^{-1}$ and $108 \times 10^{-5} \, K^{-1}$,respectively. The increase in length of each liquid is the same for the same increase in temperature. If the diameters of the capillary tubes of the two thermometers are $d_1$ and $d_2$,respectively,then the ratio $d_1: d_2$ is closest to: