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(i).1)[1]

State, for a system, what +q means.

(a(i).2)[1]

State, for a system, what +w means.

(a(ii))[1]

State what a negative value of $\Delta U$ represents.

(a(i)1)[1]

State, for a system, what +q means.

(a(i)2)[1]

State, for a system, what +w means.

(b(i))[2]

State and explain the overall change in internal energy of the gas for one complete cycle ABCA.

(b(ii))[2]

Calculate the external work done on the gas as it expands from point C to point A.

(b(iii))[4]

Complete Fig. 2.2 to show the changes from: point A to point B; point B to point C; point C to point A.

Worked solution & mark scheme

This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: transfer of energy to the system by heating

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