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Question
Find the force exerted by the water on a 2 m2 plane surface of a large stone placed at the bottom of a sea 500 m deep. Does the force depend on the orientation of the surface?
Solution
Given:
Depth of the stone from the water surface, h = 500 m
Area of the plane surface of the large stone, A = 2 m2
Density of water, ρw = 103 kgm−3
Force (F) is given by
\[F = P \times A = \left( h \rho_w \times g \right)A \left( P = \text{ Pressure }\right)\]
\[ \Rightarrow \text{ F }= \left( 500 \times {10}^3 \times 10 \right) \times 2\]
\[ = {10}^7 \text{ N/ m}^2\]
The force does not depend on the orientation of the rock when the surface area of the stone remains the same.
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