FAA Aviation Mechanic General (AMG)Physics, Math and Fluid LinesMedium
A gas sample occupies 20 cubic inches at a pressure of 100 psia. If the gas is compressed to a volume of 10 cubic inches at constant temperature, what is the new pressure?
- A200 psia
- B150 psia
- C50 psia
- D100 psia
Show answer & explanationAnswer & explanation
Correct answer: A. 200 psia
Boyle's Law states P1V1 = P2V2 at constant temperature. (100)(20) = 2,000, and 2,000 ÷ 10 = 200 psia.
Why the other options are wrong
- B. This is not consistent with the P1V1=P2V2 calculation.
- C. This results from dividing instead of using the correct inverse relationship.
- D. This assumes pressure stays the same, ignoring the volume change.
Boyle's Law
At constant temperature, the pressure and volume of a gas are inversely proportional.
- P1V1 = P2V2
- Applies only at constant temperature
- Used for compressed gas systems like oxygen or nitrogen bottles
Memory trick: Squeeze the balloon, pressure grows.