Coulomb’s Law Calculations Self Check
View the following example problem using Coulomb’s Law, then try a problem on your own. Complete the self-check activity by looking at the prompts below, working through the problems, and then clicking on the question to review the solutions.
For more practice, complete the following problems from Chapter 16 in your textbook. The answers are in the back of your book.
Problems: 1-21 odd (13 is the example below)
Tutorial: Coulomb’s Law Example
In this example, you will see Coulomb’s Law at work. Select the play button to begin the tutorial, and then use the navigation buttons to pause/stop, continue, or reset the tutorial. View the presentation as often as you would like, and take notes as you follow along. Be sure to set your volume at a reasonable level before you begin.
Problem 1
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Two positive point charges are a fixed distance apart. The sum of their charges is QT. What charge must each have in order to (a) maximize the electric force between them, and (b) minimize it?
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, then 
, where 
. A graph of 
between the limits of 0 and 1 shows that the maximum occurs at 
, or 
. Both charges are half of the total, and the actual maximized force is 
.
Problem 2
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A charge of 6.00 mC is placed at each corner of a square 0.100 m on a side. Determine the magnitude and direction of the force on each charge.
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above the x-direction. For each charge, the net force will be the magnitude determined above, and will lie along the line from the center of the square out towards the charge.
Problem 3
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At each corner of a square of side l there are point charges of magnitude Q, 2Q, 3Q, and 4Q. Determine the force on (a) the charge 2Q, and (b) the charge 3Q, due to the other three charges.
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Problem 4
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Two point charges have a total charge of
 When placed 1.10 m apart, the force each exerts on the other is 22.8 N and is repulsive. What is the charge on each? |
