AP Physics 2: Algebra-Based Practice Test (2026)

In a general-physics lab, students study a fixed quantity of an ideal gas sealed inside an insulated cylinder fitted with a frictionless piston. The cylinder is submerged in a temperature-controlled water bath held at a constant 300 K, and a contact thermometer confirms that the gas temperature remains at 300 K throughout the procedure. A student slowly pushes the piston inward, decreasing the gas volume quasi-statically. A force sensor on the piston rod and a position transducer together record the force times displacement during the compression, and the integrated reading shows that 150 J of mechanical work has been done ON the gas by the time the compression is finished. The water bath remains at 300 K, and the gas is again at rest when the work is tallied.

For this isothermal compression, how much heat is exchanged between the gas and the surrounding water bath, and in which direction does it flow?

A fixed amount of ideal gas is held in a sealed container. If the absolute temperature of the gas is doubled and its volume is simultaneously halved, what happens to the pressure of the gas?

A PV diagram shows a gas undergoing a process from state A (P = 200 kPa, V = 0.02 m³) to state B (P = 200 kPa, V = 0.05 m³) and then to state C (P = 100 kPa, V = 0.05 m³).

What is the work done by the gas during the process from state A to state B?

Gas A has a molar mass of M and is at an absolute temperature T. Gas B has a molar mass of 4M and is at an absolute temperature 2T. What is the ratio of the root-mean-square (RMS) speed of molecules in Gas A to Gas B (v_rms,A / v_rms,B)?

Two objects are in thermal contact within an isolated system. Which of the following statements MUST be true if the objects are in thermal equilibrium?

A heat engine operates by taking in 1200 J of heat from a high-temperature reservoir and expelling 800 J of heat to a low-temperature reservoir during each cycle.

What is the efficiency of this heat engine?

Which of the following processes always results in an increase in the entropy of the universe?

An ideal diatomic gas (γ = 1.4) is compressed adiabatically from an initial volume V to a final volume V/8. If the initial absolute temperature of the gas is T, what is its final absolute temperature?

For a given amount of an ideal gas, which of the following properties is *solely* dependent on its absolute temperature?

A Carnot cycle is represented on a PV diagram. It consists of four reversible processes: an isothermal expansion (A to B), an adiabatic expansion (B to C), an isothermal compression (C to D), and an adiabatic compression (D to A).

During which segment(s) of the Carnot cycle is there a net heat transfer into or out of the system?

Which of the following best describes the difference between specific heat and latent heat?

A refrigerator is designed to extract heat from its cold interior. If it removes 300 J of heat from the cold reservoir and expels 400 J of heat to the hot surroundings, what is its coefficient of performance (COP)?

Four small-scale demonstrations are run side by side in a physics classroom to compare modes of heat transfer. Demonstration 1: a student holds her hands about 0.5 m from a crackling campfire and feels a steady warmth on her palms; an infrared sensor confirms that invisible electromagnetic waves in the infrared range are reaching her from the flames, with no visible airflow between her hands and the fire. Demonstration 2: a stainless-steel spoon is placed upright in a mug of freshly brewed 85 °C coffee; after 60 seconds a temperature probe clipped to the top of the spoon's handle shows that it has warmed from 22 °C to roughly 45 °C even though no liquid has touched the upper handle. Demonstration 3: a forced-air furnace is switched on in the adjacent classroom; a blower pushes air over electric heating elements, and anemometers positioned at floor and ceiling level record a visible circulation of warm air from the vents out into the rest of the room. Demonstration 4: a pyranometer on the outside windowsill records solar radiation passing through the vacuum of space and through the glass to warm the sill, with no intervening fluid motion from the Sun.

Which of the four demonstrations described above is the clearest example of heat transfer that is primarily by convection?

An ideal gas undergoes several processes. The table below shows the heat (Q) added to the gas, the work (W) done BY the gas, and the change in internal energy (ΔU) for three different processes. Assume standard sign conventions where Q is positive if added to the system, and W is positive if done BY the system. | Process | Q (J) | W (J) | ΔU (J) | |---------|-------|-------|--------| | 1 | +100 | +40 | +60 | | 2 | -50 | -20 | -30 | | 3 | +120 | +150 | ? |

Based on the First Law of Thermodynamics, what is the change in internal energy (ΔU) for Process 3?

Which of the following statements about the entropy of a system is TRUE?

An ideal gas undergoes an isothermal expansion. Which of the following statements is true for this process?

A graph displays two Maxwell-Boltzmann distribution curves for the same ideal gas at two different absolute temperatures, T1 and T2. Curve 1 shows a peak at a lower speed and is taller, while Curve 2 shows a peak at a higher speed and is broader and lower.

Based on the description of the curves, which of the following statements about the temperatures is correct?