A small hole is made in the side wall of a large open tank at a depth 5 m below the water surface. Neglect viscosity and the speed of the falling free surface. Taking g = 10 m/s², what is the initial speed of efflux from the hole?
Options

Question

A small hole is made in the side wall of a large open tank at a depth 5 m below the water surface. Neglect viscosity and the speed of the falling free surface. Taking g = 10 m/s², what is the initial speed of efflux from the hole?

Options

G1 Physics · Accepted Answer

Apply Bernoulli's equation between the free surface and the hole. Both points are exposed to atmospheric pressure, so the pressure terms cancel. For a large tank, the free-surface speed is negligible. If the hole is at depth h, ρgh = ½ρv². Therefore, v = √(2gh). Substitute h = 5 m, g = 10 m/s². Thus, v = √(2×10×5) = √100 = 10 m/s. Correct option: B.