A pipe narrows from 0.07m2 to 0.035m2. If water flows at 2.4m/s in the wider section, what is the speed in the narrower
Continuity equation: A1v1 = A2v2. A1 = 0.07m2, v1 = 2.4m/s, A2 = 0.035m2. v2 = A1v1A2 = 0.07×2.40.035 = 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.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.