The factor not needed to calculate heat lost or gained when there is no change of state is

Water of mass $5 \ kg$ in a closed vessel is at a temperature of $20^{\circ} C$. If the temperature of the water when heated for a time of $10 \ minutes$ becomes $30^{\circ} C$, then the increase in the internal energy of the water is (Specific heat capacity of water $= 4200 \ J \ kg^{-1} \ K^{-1}$) (in $kJ$)

Derive the equation for the molar specific heat capacity of solids.

In engines,water is used as a coolant because ......

Water is used to cool radiators of engines in cars because

What is specific heat? Write its equation and unit,and on what does it depend?