# Problem P. 4128. (January 2009)

**P. 4128.** The pressure of the water supply of a city is maintained by a 24-m high water column. What is the daily electrical energy consumption of a city which has 50 000 citizens if the average water consumption of a citizen is 100 litres per day, the efficiency of the pumps is 80%, and the efficiency of the electric motors is 92%?

What is the average electrical power input of the water plant?

(4 pont)

**Deadline expired on February 11, 2009.**

### Statistics:

143 students sent a solution. 4 points: 115 students. 3 points: 10 students. 2 points: 2 students. 1 point: 8 students. Unfair, not evaluated: 8 solutions.

Problems in Physics of KöMaL, January 2009