$A$ hailstone of mass $42 \,g$ falls from a height of $1.8 \,km$. If its entire potential energy is converted into latent heat, what is the mass of the hailstone remaining when it reaches the ground (in $\,g$)? $\left(g=10 \,ms^{-2}, L_{\text{ice}}=3.36 \times 10^5 \,J \,kg^{-1}\right)$

When water is heated from $0^{\circ}C$ to $4^{\circ}C$,which of the following relations holds true?

$A$ 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 $ms^{-1}$)

The height of Victoria Falls is $63 \ m$. What is the difference in temperature of water at the top and at the bottom of the fall? (In $^{\circ}C$)
[Given $1 \ cal = 4.2 \ J$ and specific heat of water $= 1 \ cal \ g^{-1} \ ^{\circ}C^{-1}$]

Out of the following,in which vessel will the temperature of the solution be higher after the salt is completely dissolved?

If in the winter season the surface temperature of a lake is $1^{\circ} C$,the temperature at the bottom of the lake will be ............