Why does the land in a desert get hotter during the day and colder at night quickly?

The specific heat $C$ of a solid at low temperature shows temperature dependence according to the relation $C = D T^{3}$, where $D$ is a constant and $T$ is the temperature in Kelvin. $A$ piece of this solid of mass $m \ kg$ is taken and its temperature is raised from $20 \ K$ to $30 \ K$. The amount of heat required in the process in energy units is

Water is used to cool radiators of engines in cars because

$A$ small electric heater is used to heat $200 \,g$ of water. The time required to bring all this water from $40^{\circ} C$ to $100^{\circ} C$ is $200 \,s$. If the specific heat of the water is $4200 \,J \,kg^{-1} \,K^{-1}$, then the power supplied by the heater is: (in $\,W$)

Give the $SI$ unit of heat capacity. Write the dimensional formula of heat capacity.

$100 \ g$ of water is heated from $30^\circ C$ to $50^\circ C$. Ignoring the slight expansion of the water,the change in its internal energy is .......$kJ$ (specific heat of water is $4184 \ J/kg/K$):