Which statement is true about head in hydraulics?

Which statement is true about head in hydraulics?

• A. Head equals pressure in psi times 2.31 ft/psi.
• B. Head equals pressure in psi divided by 2.31.
• C. Head is independent of pressure.
• D. Head equals density times depth.

Answer: (A)

In hydraulics, head is the height of a water column that would produce a given pressure. For water, the relationship is P = γ h, where γ is the unit weight of water (about 62.4 lbf/ft^3). If the pressure is given in psi, convert to pounds per square foot by multiplying by 144, then solve for the head in feet: h = P/γ = (P_psi × 144) / 62.4 ≈ P_psi × 2.31 ft/psi. So the statement that head equals pressure in psi times 2.31 ft per psi is correct because 1 psi corresponds to roughly 2.31 feet of water head. This ties to head being a length measure of energy per unit weight, derived from the fact that pressure is the product of unit weight and head. The idea that head is pressure divided by 2.31 would misapply the conversion, and saying head is independent of pressure or that it equals density times depth ignores the proper relation P = γ h and the need to use weight density γ (not just density) with consistent units.

In hydraulics, head is the height of a water column that would produce a given pressure. For water, the relationship is P = γ h, where γ is the unit weight of water (about 62.4 lbf/ft^3). If the pressure is given in psi, convert to pounds per square foot by multiplying by 144, then solve for the head in feet: h = P/γ = (P_psi × 144) / 62.4 ≈ P_psi × 2.31 ft/psi. So the statement that head equals pressure in psi times 2.31 ft per psi is correct because 1 psi corresponds to roughly 2.31 feet of water head. This ties to head being a length measure of energy per unit weight, derived from the fact that pressure is the product of unit weight and head. The idea that head is pressure divided by 2.31 would misapply the conversion, and saying head is independent of pressure or that it equals density times depth ignores the proper relation P = γ h and the need to use weight density γ (not just density) with consistent units.