Question

A pump on the ground floor of a building can pump up water to fill a tank of volume 30cubic meter in 15min .If the tank is 40m above the ground and the efficiency of the pump is 30%how much electric power is consumed by the pump

Answer 1

Density of water is = 1000 kg/m3

Volume of water filled = 30 m3

Therefore, mass of water filled in the tank = (1000 kg/m3)(30 m3) = 30000 kg

Height to which the water is raised = 40 m

Acceleration due to gravity = 9.8 m/s2

So, rise in potential energy of the water = (30000 kg)(9.8 m/s2)(40 m) = 1.17 X 107 J

The work is done by the pump in 15 min = 900 s

Power of the pump = (1.17 X 107 J)/(900 s) = 13000 Watt

Let, x be the electrical power given to the pump, since the efficiency of the pump is 30%

Therefore,

x(30/100) = 13000

=> x = 43333.33 Watt

So, the power consumed by the pump is 43333.3 Watt.

Answer 2

⛦Hᴇʀᴇ Is Yoᴜʀ Aɴsᴡᴇʀ⚑
▬▬▬▬▬▬▬▬▬▬▬▬☟

➧ The volume of the tank is
➾ 30 

➧ Mass of the water is
➾ 30 × 1000 kg
➾ 30000kg 

➧ Time = 15 min
➾ 15 × 60
➾ 900s 

➧ Height
➾ 40 m 

➧ Total work done by the pump
➾ F × h= mgh
➾ 30000 × 9.8 × 40
➾ 11760000 J 

➧ Power = W/t
➾ 11760000 / 900
➾ 13066.67 watt 

➧ Efficiency = 30%
➾ 3 / 10 

➧ Required power
➾ 13033.67 × 10 / 3
➾ 43.56 kW ...✔

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Thanks...✊