Quelpr
3 marksFirst Law of Thermodynamics

CAPE Physics Unit 1 · May/June 2024 · Paper 2 · Question 3(c)

The first law of thermodynamics is given by ΔU = Q + W. Explain the meaning of EACH symbol when applied to the heating of a fixed mass of gas.

The mark scheme is shown once you've answered.

Practise this question

Other parts of this question

  1. 3(a)Write the equation of state for an ideal gas, stating the meaning of EACH symbol.[3 marks]
  2. 3(b)(i)Complete Column 3 of Table 2 by calculating the volume of gas, V/mm³.[1 mark]
  3. 3(b)(ii)On the grid provided in Figure 5, plot a graph of volume of gas, V, versus temperature, t, using scales ranging from -325 °C to +100 °C on the temperature axis…[4 marks]
  4. 3(b)(iii)From the graph in 3(b)(ii), determine the temperature at which the volume is 0 mm³.[2 marks]
  5. 3(b)(iv)State whether it is possible to achieve a state of zero volume for the gas if it is cooled sufficiently. Justify your response.[2 marks]
  6. 3(b)(v)State the gas law which explains the observations in this experiment.[2 marks]
  7. 3(d)(i)Calculate the work done during the cycle.[2 marks]
  8. 3(d)(ii)Calculate the temperature, T₂, at State 2.[3 marks]
  9. 3(d)(iii)Calculate the energy added as heat during the process from State 1 to State 2.[4 marks]
  10. 3(d)(iv)Derive an expression for Cₚ for the gas in terms of R.[2 marks]
  11. 3(d)(v)State TWO reasons why the cycle in Figure 6 is NOT 100% efficient.[2 marks]

More practice: the rest of this paper · more First Law of Thermodynamics questions · all CAPE Physics Unit 1 past papers