Answer: (1/2)k BT.
- A k<sub>BT</sub>
- B (1/2)k<sub>BT</sub>
- C (3/2)k<sub>BT</sub>
- D 2k<sub>BT</sub>
Correct answer: B. (1/2)k<sub>BT</sub>
Explanation: According to the law of equipartition of energy, each quadratic degree of freedom contributes (1/2)k<sub>BT</sub> of average energy per molecule.
Not all gas molecules move at the same speed - the Maxwell-Boltzmann distribution shows the spread, with the most probable speed vp slightly less than the average vavg, which is slightly less than the root-mean-square speed vrms used in the pressure formula.
Concept context
Kinetic theory of gases connects molecular motion to pressure and temperature, explaining gas laws, specific heats, and molecular speeds.