IB Physics B.4 Thermodynamics Questionbank

A sealed cylinder contains a monatomic ideal gas. The gas is compressed from a volume of $0.80\ \text{m}^3$ to $0.40\ \text{m}^3$ at constant temperature.

(a) Define the term “isothermal process.”

Energy is conserved in all interactions.

The number of accessible microstates always decreases in an isolated system.

Entropy increases because systems evolve toward macrostates with the highest probability.

The work done by an engine can be completely converted into heat.

$\Delta S = \frac{Q}{T}$

$\Delta S = mc\Delta T$

$\Delta S = \frac{W}{T}$

$\Delta S = P\Delta V$

(b) State what happens to the internal energy of the gas during this process and explain your answer.

(c) The pressure-volume graph below represents this isothermal compression.

Explain what the area under the curve physically represents.

(d) The area under the curve is numerically equal to $3500\ \text{J}$. Using the first law of thermodynamics, determine the amount of thermal energy transferred to or from the gas. State whether it is into or out of the gas.