Physics 9702 · AS & A Level · The first law of thermodynamics
The first law of thermodynamics — practice question
The first law of thermodynamics can be written as $\Delta U = q + w$.
(a)[3]
Explain the meaning of the symbols in this expression: $\Delta U$, $q$ and $w$.
(b(i))[3]
State what is meant by specific latent heat.
(b(ii))[3]
Use the first law of thermodynamics to explain why the specific latent heat of vaporisation is greater than the specific latent heat of fusion for a particular substance.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “$+\Delta U$: rise in internal energy” …