alleryA pump lifts water at a rate of 3000 kg per minute through 30 m (g = 10 m s⁻²). The minimum power of the pump is:
A5 kW
B10 kW
C15 kW
D20 kW
Answer & Solution
Correct answer: C. 15 kW
1. Mass per second = 3000 / 60 = 50 kg s⁻¹.
2. Power needed = (dm/dt) · g · h = 50 × 10 × 30 = 15 000 W.
3. = 15 kW.
4. This is the minimum — real pumps need more due to losses.
_Source: syllabus Physics Ch 5, §5.10 Power_
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