Physicshard · Past Paper
A pump can lift 100 kg of water to a height of 100 m in 10 s. If efficiency is 50%, what is the input power?
A10 kW
B20 kW
C5 kW
D40 kW
✓ Correct Answer: B — 20 kW
Output Power = mgh/t = (100*10*100)/10 = 10,000 W. Input = Output/Eff = 10,000 / 0.5 = 20,000 W = 20 kW.
Share this question
More from Physics
- What is the relationship between force (F), mass (m), and acceleration (a)?
- The value of G is:
- Which of the following describes 'free fall'?
- The force that binds the solar system is:
- Three resistors of 1, 2, and 3 Ohms are connected in series. The potential difference across the 2 Ohm resistor if the total voltage is 12V is: