What is the increase in friction loss when the flow rate of a hose increases from 50 gpm to 200 gpm?

• A. 12 psi
• B. 20 psi
• C. 32 psi
• D. 50 psi

Answer: (C)

To determine the increase in friction loss when the flow rate of a hose increases, it's important to understand the relationship between flow rate and friction loss. Friction loss increases with the square of the flow rate, which means that if the flow rate doubles, the friction loss does not simply double; instead, it increases by a factor of four.

In this scenario, the flow rate increases from 50 gallons per minute (gpm) to 200 gpm. To analyze this:

1. Calculate the flow rate increase factor:

• 200 gpm is four times greater than 50 gpm.

2. Since friction loss is proportional to the square of the flow rate, the increase in friction loss when moving from 50 gpm to 200 gpm can be calculated as:

• (200 gpm / 50 gpm)² = 4² = 16

3. If the friction loss at 50 gpm is known, then at 200 gpm, the friction loss will be 16 times greater.

Since the question pertains to the increase in friction loss rather than the absolute value, one would look at the difference. Assuming a base friction loss at 50 gpm is 4 psi (