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Homework Help: Electric flux through a box

  1. Jan 28, 2009 #1
    1. The problem statement, all variables and given/known data
    A empty cardboard box is placed in an electric field pointing upwards with a strength of 1100 N/C as shown above. The bottom of the box is tilted up by an angle Θ = 19° from the horizontal. Side A of the box faces out of the page and is 10 cm high and 14 cm long. Sides B and C are 10 cm high and 12 cm deep. Sides D and E are 14 cm long and 12 cm deep.

    calculate flux through each side of the box
    2. Relevant equations
    I have the equation Flux=EAcostheta

    3. The attempt at a solution
    (1100)(120)(cos71) did not give me the right answer, so I thought I would try cos19, but that also didn't work. ( that is for side B) i'm not sure if i'm missing something conceptually, I also tried the negatives for both of these answers, the flux is flowing through the side, to my understanding, i dont see when the flux would NOT be going through the side in order to get a negative result. If someone could help me grasp where i'm going wrong with one of the sides i would greatly appreciate it.
  2. jcsd
  3. Jan 29, 2009 #2


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    Hi zooboodoo! :smile:

    :confused: which is the base of the box? which edge is still on the table? :smile:
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