Question

The pressure at a depth of 5 m below the surface of the sea water, considering sp. gravity of water to be 1.3, will be
1. 63765 Pa
2. 637650 Pa
3. 1.27 × 10⁸ Pa
4. 1.27 × 10⁹ Pa

Answer 1

Correct Answer - Option 1 : 63765 Pa

Concept:

• The normal force exerted by liquid at rest on a given surface in contact is called the thrust of liquid on that surface.
• The normal force (or thrust) exerted by liquid at rest per unit area of the surface in contact with it, is called pressure of liquid or hydrostatic pressure.
• If P is the pressure for a point at depth h below the surface of a liquid of density ρ.

Hydrostatic pressure P is given by P = ρgh

Calculation:

Given:

Height (h) = 5 m, density of water (ρ) = 1.3 × 103 kg/m3

The pressure at a depth of 5 m is:

⇒ Pa = ρgh 

⇒ Pa = 1.3 × 103 × 9.81 × 5 =  63765 Pa

Hence the required pressure at the given depth is 63765 Pa