$250\,g$ of water and an equal volume of alcohol of mass $200\,g$ are placed successively in the same calorimeter and cool from $60^{\circ}C$ to $55^{\circ}C$ in $130\,s$ and $67\,s$ respectively. If the water equivalent of the calorimeter is $10\,g$,then the specific heat of alcohol in $\text{cal/g}^{\circ}C$ is:

In cold countries,water pipes sometimes burst,because

$A$ 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 $\,g$)? $\left(g=10 \,ms^{-2}, L_{\text{ice}}=3.36 \times 10^5 \,J \,kg^{-1}\right)$

$A$ lead bullet of mass $50 \ g$ at a temperature of $30^{\circ}C$ is fired vertically upwards with a speed of $840 \ m/s$. When the bullet returns to the point of departure,it strikes a large block of ice at $0^{\circ}C$. How much ice (in $g$) will melt? (Specific heat of lead is $0.02 \ cal/g^{\circ}C$,latent heat of fusion of ice is $80 \ cal/g$,and assume all energy is used to melt the ice.)

How much energy will be released by cooling $1\,kg$ of water up to a temperature of $10\,^{\circ}C$?

$A$ 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).