A downward water jet narrows from diameter 6 mm to 3 mm over a vertical drop of 3 cm. Neglect viscosity and surface tension. If the volume flow rate is (xπ) mL/min, find x. Image
Physics · Fluid Mechanics
JEE Mains Advanced

Question

A downward water jet narrows from diameter 6 mm to 3 mm over a vertical drop of 3 cm. Neglect viscosity and surface tension. If the volume flow rate is (xπ) mL/min, find x. Image

G1 Physics · Accepted Answer

Step 1: Use surface-energy/pressure relations: ΔP = 2T/R for a liquid drop or 4T/R for a soap bubble, capillary rise h = 2T cosθ/(ρgr), and surface energy = TΔA. Step 2: Apply force or energy balance to the stated radii and surface areas. Applying these relations to the given data gives 108. Final answer: 108.