# Homework Help: Help with 3 questions for general physics?

1. Sep 19, 2009

### sweetipie2216

1.Three point charges are fixed in place in the right triangle diagrammed below, in which q1 = 0.81 µC and q2 = -0.53 µC. What is the electric force on the +1.0 µC charge due to the other two charges,degree measured counterclockwise from the +x-axis?

2. Two Styrofoam balls with the same mass m = 8.7 10-8 kg and the same positive charge Q are suspended from the same point by insulating threads of length L = 0.91 m (the figure below). The separation of the balls is d = 0.028 m. What is the charge Q?

3.Positive point charges are placed at three corners of a rectangle, as shown in the figure, in which d = 0.41 m. Take the +x-axis to point to the right.
(a) What is the electric field at the fourth corner?
degrees measured counterclockwise from the -x-axis

(b) A small object with a charge of +8.8 µC is placed at the fourth corner. What force acts on the object?
degrees measured counterclockwise from the -x-axis

here is a link to the diagrams. http://s685.photobucket.com/albums/vv220/sweetipie2216/

each picture is labeled with the question number.
I did work on these questions. I asked my teacher and T.A for help and they just added more to the confusion.

Here are my answers for number 3. I dont know if they are right or wrong. a)5.63e6N,205 degrees b)49.58N and 205 degrees.
If you can please give me a good explanation about how i can solve these with good detail and showing all the steps. You dont have to give me any answers.

Last edited: Sep 19, 2009