1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Power question.

  1. Oct 4, 2004 #1
    Water flows over a section of Niagara Falls at
    a rate of 1.38 x 10^6 kg/s and falls 32 m.
    The acceleration of gravity is 9.8 m/s2 .
    How many 80 W bulbs can be lit with this
    power?
     
  2. jcsd
  3. Oct 4, 2004 #2
    Force = Mass*Acceleration, which in this case will be in newtons.
    P = Force*distance / time, note that force*distance is also called "work" and the units of work are "Joules". A watt is Joules over time, which is exactely what this equation comes up with.

    That should be all you need to know.
     
  4. Oct 4, 2004 #3
    thanks for the help.
     
  5. Oct 5, 2004 #4
    If i am not mistaken, here we have to use Newton's second law in real form that's
    f=d/dt(m*v)
    here velocity is not the variable but the mass (check kg/s)
    work done = f*d/time

    you can do the rest.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Power question.
  1. Power question (Replies: 1)

  2. Power Question (Replies: 3)

  3. Question on Power (Replies: 1)

  4. Power question (Replies: 7)

Loading...