The question is : A pump is required to lift 800kg of water per minute from a we

Question

The question is :
A pump is required to lift 800kg of water per minute from a well14m deep and eject it with a speed of 18m/s. Part A) How much work is done per minute in lifting thewater? For part A, isnt the question asking for power? after all,power is the change in work over time hence "work done permin." How does one know if its asking for power or work? The question is :
A pump is required to lift 800kg of water per minute from a well14m deep and eject it with a speed of 18m/s. Part A) How much work is done per minute in lifting thewater? For part A, isnt the question asking for power? after all,power is the change in work over time hence "work done permin." How does one know if its asking for power or work?

Explanation / Answer

yeah... the question was vague. It said the water was liftedAND ejected at a speed of 18 m/s. . The work required to lift it was    mgh =800 * 9.80 * 14 =    110,000 Joules . and the work to give it its speed, i.e. the kinetic energy,is    (1/2) m v2 =    130,000 Joules . Technically only the 110,000 is done to lift it,but since it is also given kinetic energy, the work done in theprocess is the sum of the two...    240,000Joules . It's a poorly written question, so it's difficult to give theanswer they think you should give.

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