Hydrostatic Pressure Dependence

Steps:

• Pressure at depth in a liquid combines atmospheric pressure and hydrostatic contribution.
• Hydrostatic pressure is ρ g d, where g is gravitational acceleration.
• Total pressure P = p + ρ g d, depending on p (atmospheric), ρ (density), and d (depth).
• Since g is constant, P varies with the product-like term ρ d alongside p.

Why B is correct:

• The formula P = p + ρ g d shows pressure depends on d, ρ, and p, matching the variables in B (d ρ p).

Why the others are wrong:

• A: Ignores ρ; pressure increases with density, not just d + p.
• C: Subtraction d - p implies reduced pressure with depth, contradicting hydrostatic increase.
• D: Subtraction ρ - d ignores p and misrepresents depth's multiplicative role with density.

Final answer: B