Power

Practice Questions:

Question 1: easy

An engine pumps 400 kg of water through height of 10 m in 40 s. Find the power of the pump (g = 10 m/s²).

1. 500 W

2. 750 W

3. 1000 W

4. 1250 W

View Answer

Power = Work Done / Time Taken

Here , Work Done = 400 ×10 ×10 J = 40000 J

Time Taken = 40 sec , So,

Power = 40000/40 = 1000 W= 1 KW

💬 Discuss this Question

Question 2: easy

A force F = (iˆ + ˆj + 2kˆ) N is acting on a particle moving with constant velocity v = (iˆ + ˆj + kˆ) m/s. Power delivered by force is

1. 3 Watt

2. 4 Watt

3. 5 Watt

4. 6 Watt

View Answer

Power is dot product of Force and Velocity

P = F.v

⇒ P= (iˆ + ˆj + 2kˆ). (iˆ + ˆj + kˆ)= 1+1+2= 4 watt