Which of the following sets of variables are typically used to describe the pressure exerted by a gas in a piston system?

• A. $F$ (force), $m$ (mass), $g$ (acceleration due to gravity)
• B. $I$ (current), $R$ (resistance), $V$ (voltage)
• C. $q$ (charge), $t$ (time), $c$ (speed of light)
• D. $P$ (pressure), $V$ (volume), $T$ (temperature), $n$ (number of moles)

Answer: (D)

Verified step by step guidance

1. Understand that pressure exerted by a gas in a piston system is typically described using variables related to the state of the gas, such as pressure (P), volume (V), temperature (T), and amount of substance (n).
2. Recall the ideal gas law, which relates these variables: \(P \times V = n \times R \times T\), where \(R\) is the ideal gas constant.
3. Recognize that force (F), mass (m), and acceleration due to gravity (g) are more related to mechanics and weight, not directly describing gas pressure in this context.
4. Note that current (I), resistance (R), and voltage (V) are electrical variables and do not describe gas properties.
5. Understand that charge (q), time (t), and speed of light (c) are unrelated to gas pressure in a piston system.