In the horsepower calculation example, what is the weight in pounds per minute derived from the flow rate of 175 gpm?

In the horsepower calculation example, what is the weight in pounds per minute derived from the flow rate of 175 gpm?

• A. 7.4805
• B. 8.34
• C. 62.4
• D. 3.14

Answer: (B)

To convert flow rate in gallons per minute to weight flow in pounds per minute, you use the fluid’s density expressed as pounds per unit volume. For water, that density is 8.34 pounds per gallon. In the horsepower calculation, this density serves as the conversion factor that turns gallons per minute into pounds per minute. So, with a flow of 175 gpm, you’d multiply by 8.34 to get the weight flow in pounds per minute (175 × 8.34 = 1459.5 lb/min). Among the options, 8.34 is the density factor used in that conversion, while the other numbers correspond to related constants (62.4 lb/ft³ for water density in pounds per cubic foot, 7.4805 gallons per cubic foot, and 3.14 for pi). That’s why 8.34 is the appropriate choice.

To convert flow rate in gallons per minute to weight flow in pounds per minute, you use the fluid’s density expressed as pounds per unit volume. For water, that density is 8.34 pounds per gallon. In the horsepower calculation, this density serves as the conversion factor that turns gallons per minute into pounds per minute. So, with a flow of 175 gpm, you’d multiply by 8.34 to get the weight flow in pounds per minute (175 × 8.34 = 1459.5 lb/min). Among the options, 8.34 is the density factor used in that conversion, while the other numbers correspond to related constants (62.4 lb/ft³ for water density in pounds per cubic foot, 7.4805 gallons per cubic foot, and 3.14 for pi). That’s why 8.34 is the appropriate choice.