In each minute a pump draws 2.4m³ of water from a well 5m below ground, and issues it at ground level through a pipe of cross-sectional area 50cm². find:
a) The speed with which the water leaves the pipe
b) the rate at which the pump is working.
If in fact the pump is only 75% efficient (i.e. 25% of the power is lost in the running of the pump), find the rate at which it must work.
2007-09-09 16:23:46 · 1 answers · asked by A Freak Like Me 2 in Science & Mathematics ➔ Mathematics
1. Since velocity = Volume flow/area, the volume flow is 2.4x10^6 cc/min or 4x10^4 cc/sec. Then you figure out speed in cm/sec.
2. The pump accomplishes 2 tasks. While you use the term "work", the proper term is "power".
The first task is raising the potential energy of 40 kg of water 5m per second. AND the second, increasing the kinetic energy of 40 kg of water from 0 to the answer of (a) per second =(mv^2/2)
From your information, you should be able to come up with the answer.
2007-09-09 16:37:31 · answer #1 · answered by cattbarf 7 · 0⤊ 0⤋