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Grade upto college level Mechanics

The top surface of an incompressible liquid is open to the atmosphere. The pressure at a depth h1 below the surface is p1∙ How does the pressure p2 at depth h2 = 2div compare with p1?
(A) p2 > 2p1 (B) P2 = 2p1 (C) P2 p1

Profile image of Amit Saxena
11 Years agoGrade upto college level
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1 Answer

Profile image of Navjyot Kalra
11 Years ago

The pressure at a given depth in an incompressible liquid is given by the hydrostatic pressure equation:

p = p₀ + ρgh

where:

p is the pressure at depth h,
p₀ is the atmospheric pressure at the surface,
ρ is the density of the liquid,
g is the acceleration due to gravity,
h is the depth below the surface.
Given that at depth h₁, the pressure is:

p₁ = p₀ + ρgh₁

At depth h₂ = 2h₁, the pressure is:

p₂ = p₀ + ρg(2h₁)

Expanding this:

p₂ = p₀ + 2ρgh₁

Since p₁ = p₀ + ρgh₁, we substitute this into the equation for p₂:

p₂ = p₀ + 2ρgh₁ = 2(p₀ + ρgh₁) - p₀
= 2p₁ - p₀

Since atmospheric pressure p₀ is a positive value, we see that:

p₂ < 2p₁

Thus, the correct answer is:

(C) p₂ < 2p₁

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