A uniform wooden plank of length 1 m and specific gravity 0.5 is hinged at one end to the bottom of a tank. Water depth is 0.5 m. Find the equilibrium angle θ made by the plank. Image
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A uniform wooden plank of length 1 m and specific gravity 0.5 is hinged at one end to the bottom of a tank. Water depth is 0.5 m. Find the equilibrium angle θ made by the plank. Image

G1 Physics · Accepted Answer

Step 1: Use continuity A₁v₁ = A₂v₂ and Bernoulli's equation P + ½ρv² + ρgh = constant; for jets use momentum flux ṁΔv. Step 2: Substitute the stated areas, levels and pressures, including Torricelli v = √(2gh) where applicable. Applying these relations to the given data gives A: 45°. Final answer: A.