Practice question
Question
A pipe’s cross-sectional area changes from 0.08m2 to 0.02m2. If the speed at the larger end is 1.2m/s, what is the speed at the smaller end?
Explanation
Continuity equation: A1v1 = A2v2. A1 = 0.08m2, v1 = 1.2m/s, A2 = 0.02m2. v2 = A1v1A2 = 0.08×1.20.02 = 4.8m/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 4.8 m/s. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.