A gas strut is used to raise a heavy inspection cover. The strut contains a fixed mass of nitrogen behind a tightly fitting piston.
With the cover closed, the nitrogen has a volume of 75 cm3 and a pressure of 1.8 MPa. When the catch is released, the nitrogen expands rapidly to 225 cm3 as the piston raises the cover.
The cylinder walls remain at room temperature.
Calculate the pressure of the nitrogen after expansion if its temperature did not change.
Use the equation
P1×V1=P2×V2P_1 \times V_1 = P_2 \times V_2P1×V1=P2×V2
The pressure recorded when the volume reaches 225 cm3 is much lower than your answer to (a).
Explain why.
The cover is raised again so that the nitrogen reaches the same final volume much more slowly.
Explain why the decrease in the temperature of the nitrogen is smaller.
108 exam-style questions on Edexcel GCSE Physics 14.3 Gas pressure and temperature, covering 14.3.1 Gas pressure and particle motion, 14.3.2 Temperature and pressure at constant volume, 14.3.3 Absolute zero and the kelvin scale, 14.3.4 Compressing and expanding gases, 14.3.5 Volume and pressure at constant temperature, and 14.3.6 Doing work on a gas. Each one has a worked solution and a mark scheme showing where the marks go.