Past exam of the medicine course of the University of Oxford / 1867 / First examination / Physics / 9 / Solution

Specific heat capacity is heat capacity per unit mass. For a specified thermodynamic process without a phase transition,The constraint matters: constant-pressure and constant-volume heat capacities need not coincide. Here the supplied iron value and water value are treated as constants.

At the stipulated barometer reading, iron left in boiling water reaches $100^{\circ }\mathrm{C}$. Taking water's specific heat capacity as one in the given units, the iron has heat capacity $100(0.114)=11.4$. The adhering gramme of hot water adds another one. Thus the hot material has total heat capacity $12.4$, compared with $150$ for the initially cool water.

The no-loss calorimetry energy balance issoThe adhering water enters on the hot side, not as extra water initially at $10^{\circ }\mathrm{C}$. The vessel's heat capacity is neglected, as none is supplied.