Question 21
PressureThe water manometer in Fig. 2 is measuring the pressure of the gas supply. If the specific gravity of mercury is 13.6 and the atmospheric pressure is 70 cm of mercury, what is the total pressure of the gas supply in cm of water?
- A.67 cm
- B.73 cm
- C.949 cm
- D.952 cm
- E.955 cm
Show the answer and explanation
Answer: E (955 cm)
Explanation
Atmospheric pressure = 70 × 13.6 = 952 cm of water. The water in the open arm stands 3 cm higher, so the gas pressure is 952 + 3 = 955 cm of water.