1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Intensity from sun

  1. Sep 20, 2014 #1
    Sun emits 153.6 x 10^15 J of energy onto a region that is 20km by 20km in area. The intensity of the sun on this region is 685W/m^2. How many days would it take for the sun to put that amount of energy onto the region?

    I went intensity = power/area and got to a time of some 44000seconds, however this does not convert to the correct number of days of 6.5days.
    Where have I gone wrong?
  2. jcsd
  3. Sep 20, 2014 #2


    User Avatar

    Staff: Mentor

    To spot your error we need to see your working. :confused:

    Show us your equation involving just one unknown, viz., time

    If you include units along with magnitudes in all your equations, you will usually see where you are making mistakes, because you can cancel units just as you can cancel numbers.
  4. Sep 20, 2014 #3
    thanks solved it
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted