NTA Abhyas JEE Main2020PhysicsMechanical Properties of FluidsPractice
A wide cylindrical vessel 50 cm in height is filled with water and rests on a table. Assuming the viscosity to be negligible, find at what height (in cm ) from the bottom of the vessel a small hole should be perforated for the water jet coming out of it to hit the surface of the table at the maximum distance from the vessel?
Correct answer
25
Step-by-step solution
Applying Bernoulli's theorem just inside (at point (1)) and just outside of hole (at point(2)). ∵ P 1 ρ g + v 1 2 2 g + y = P 2 ρ g + v 2 2 2 g + y Here v 1 = 0, P 2 = P 0 = atmospheric pressure. P 1 = P 0 +ρg (H – y) v 2 = v Putting the values, we obtain 1 2 ρ v 2 = H - y ρ g ∴ v = 2 g H - y In horizontal direction Horizontal range, l = vt For vertical motion, y = 1 2 gt 2 ∴ t = 2 y g ∴ l = 2 g H - y 2 y g = 2 y H - y For the maximum value of l , d l d h = 0 After solving, y = H 2 = 2