Available practice: 94 of 100 marks. Parts 3(a)(i), 7(a), 8(a) await marking support. Scores cover available parts only.
(a)(ii)Use one of the basic assumptions of the kinetic theory to explain what can be deduced about the potential energy associated with the random motion of molecules in an ideal gas.
Answer guidance
Using You must use the thing it names. An answer that reaches the right value another way may not score.
[2 marks]
A sample of 0.26 m³ of an ideal gas is at pressure 2.0 × 10⁵ Pa and temperature 290 K.
(b)(i)Determine the number N of molecules of the gas.
Answer guidance
Determine Work it out from what you are given or from the figure, and show how you got there.
[2 marks]
(b)(ii)Determine the average translational kinetic energy E_K of one molecule of the gas.
Answer guidance
Determine Work it out from what you are given or from the figure, and show how you got there.
[2 marks]
(b)(iii)Determine the internal energy of the gas. Explain your reasoning.
Answer guidance
Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.
[2 marks]
A sample of 0.26 m³ of an ideal gas is at pressure 2.0 × 10⁵ Pa and temperature 290 K. The volume V of this gas is now varied, keeping its pressure constant.
(c)On Fig. 3.1, sketch the variation with V of the internal energy U of the gas.
[2 marks]
9702/41/M/J/24Cambridge International AS & A Level Physics 9702 · May/June 2024 · Paper 4 variant 1 · Question 3
