A horizontal hole of area 2 cm² is situated 5 m below the water surface of a large open tank. Taking ρ = 1000 kg/m³ and g = 10 m/s², the reaction force on the tank due to the outgoing jet is N N. Find N.
Physics · Fluid Mechanics · equation of continuity and bornullie theorem
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Question

A horizontal hole of area 2 cm² is situated 5 m below the water surface of a large open tank. Taking ρ = 1000 kg/m³ and g = 10 m/s², the reaction force on the tank due to the outgoing jet is N N. Find N.

Physics · Fluid Mechanics · equation of continuity and bornullie theorem

G1 Physics · Accepted Answer

Efflux speed satisfies v² = 2gh = 100. The jet thrust is F = ṁv. Since ṁ = ρav, we have F = ρav². Convert area: a = 2 cm² = 2×10⁻⁴ m². Therefore, F = 1000×2×10⁻⁴×100 = 20 N. Hence, N = 20.