Head pressure is calculated by multiplying the total vertical difference in feet by which constant?

Head pressure is calculated by multiplying the total vertical difference in feet by which constant?

• A. Multiplying the total difference in feet by 0.434 psi
• B. Multiplying by 0.5 psi per foot
• C. Dividing the total feet by 0.434 psi
• D. Adding 0.434 psi per foot

Answer: (A)

The amount of pressure from a column of water increases directly with how high the column is. For water, the pressure increase per foot of height is about 0.433 psi. So the total head pressure is the vertical difference in feet multiplied by 0.433 (approximately 0.434) psi per foot. That makes multiplying by 0.434 the correct way to convert head in feet to pressure in psi. The other ideas don’t fit the relationship: using a fixed 0.5 psi per foot is not accurate for water; dividing by 0.434 would invert the relationship (giving feet from psi), and adding 0.434 psi per foot would accumulate pressure in a way that doesn’t reflect how hydrostatic pressure scales with height.

The amount of pressure from a column of water increases directly with how high the column is. For water, the pressure increase per foot of height is about 0.433 psi. So the total head pressure is the vertical difference in feet multiplied by 0.433 (approximately 0.434) psi per foot. That makes multiplying by 0.434 the correct way to convert head in feet to pressure in psi.

The other ideas don’t fit the relationship: using a fixed 0.5 psi per foot is not accurate for water; dividing by 0.434 would invert the relationship (giving feet from psi), and adding 0.434 psi per foot would accumulate pressure in a way that doesn’t reflect how hydrostatic pressure scales with height.