Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Physics help

  1. Oct 10, 2004 #1
    can someone give me some clues or help as to how i'm supposed to go about solving the following problem? my professor has not covered any of the material from this chapter, so i have no idea how to even start this. the question is:

    the motor on a water pump is rated at 6.6 hp. from how far down a well can water be pumped up at the rate of 220 gal/min ?

    thanks for any help.
  2. jcsd
  3. Oct 10, 2004 #2
    See if maybe your textbook will give you any clues. The 6.6 horsepower rated engine -I'm supposing that means the most it can "crank out" at once- can exert a force on the water equal to approximately 968822.58 Newtons. I get this number through the conversions 1 hp = 33,000 foot-pounds a minute, and 33,000 foot-pounds is right around 1.467913*10^5 Newtons according to the unit converter on my calculator, and then you simply multiply by 6.6. I'm thinking that since the question uses gal/min and 1 hp is 33,000 foot-pounds per minute that you can cancel out time and just deal with newtons and gallons. I'm not keen on all physics equations, but I hope that this will simplify the work for you.
  4. Oct 10, 2004 #3
    Lets call the depth as d,
    the rate at which it is to be pumped say r,
    the power of the motor say p...

    look through ur text and see how can u relate these quantities?

    -- AI
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook