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Grade 11 physics help

  1. Dec 13, 2006 #1
    hey ive got a few questions that i would like some help with. Im new to these forums but if you could post your steps to the awnser, with an explanation that would be great.

    1. Two metal sphers, one having a charge of 4 * 10^-6 C and the other having a charge of 2 * 10^-6 are 3 cm apart. If k = 9 *10^9 Nm^2C^-2. what is the electrical force between them.

    2. A toaster draws a current of .5 A when making toast. If it takes a total charge flow of 60.00 at 120.0 V to tast a bagel, how many minutes will the toaster take?

    3. A clothes dryer is connected to a 240.0v line draws 10.00 A of current for 20.00 minutes. Approximatley how much electrical energy does the dryer consume?

    4. A peice of wire 5 m long has a resistance of 2 ohm. Determine the resistance of another peice of wire made of the same material but which is 10m long and has triple the diameter. Explain your reasoning.

    5. A bird stands on an electric transmission line that is carrying a current of 140.0 A. The line has 2.3 * 10^-4 ohm/m if the birds feet are 2.5 cm apart what voltage does the bird feel.

    6. a total resistance of 3.00 ohm is to be produced by a connection an unkown resistance to a 12.00 ohm resistance. What must be the value of the unkown resistance and how should it be connected.

    7. what is the source of magnetism at the atomic level?

    8. What is a cow magnet and how is it used?

    9. Apply the motor principle to explain the curvatur of comet tails.

    Thanks alot!
    if you need any clarifying because i made a typo just ask. And if a number seems wrong it might be i made a mistake so just say so. Thanks agian.
  2. jcsd
  3. Dec 13, 2006 #2
    Normally we don't provide answers without some sort of effort made on the person requesting aid. Show what you've done, or what you think, and then we'll feedback. To me this just looks like a homework assignment... :bugeye:
  4. Dec 14, 2006 #3
    Well its actually a bonus assignment. I need to boost my mark with. We havent started the unit on electricty and magnetism yet. Any formulas to use for each questino would be helpfull too.
  5. Dec 14, 2006 #4
    Being a bonus assignment, it sounds as if we'd be helping you "cheat" on the assingment. If you were to try the questions, and show us that you have given an effort, then we would lead you to the right answer.

    ((If an administrator is reading this, please correct me if I'm wrong about this..))
  6. Dec 15, 2006 #5


    User Avatar

    Staff: Mentor

    You're 100% correct.

    But since I'm a Mentor, I can cheat a little and give him the answer to the cow magnet question #8. I grew up in the country and saw them used. Pretty amazing stuff. A cow magnet is a magnet shaped like a cow. It is used to attract aliens.:tongue2:

    Well, if you really want to know what a cow magnet is, just google "cow magnet" and get the extra credit! o:)
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