- #1
dmullin4
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Homework Statement
This is from a lab program for my class. Its set on a grid where I can place charges and use the mouse pointer to find the intensity of the field at any spot. I am using the E values I got from hovering my mouse over the indicated spot (x, y).
I have a positive 10 microcoulomb charge at (-140, 140). I have determined at (-100, 100), E=28.12 microcoulomb. They are asking me to find the constant of proportionality "k" at that point. I also have E=7.03 at (-60, 60), E=2.30 at (0, 0), and E=0.57 at (140, -140).
Homework Equations
E=[k*q*r(hat)]/r^2
The Attempt at a Solution
28.12 = [k*10*56.6]/56.6^2
k = 159.2
I'm not sure about my r(hat) variable. I understand it to be the vector pointing from the charge to the other point. I used the distance formula to get r=56.6. q=10 microcoulomb is given in the problem. When I performed this equation for the next data set (-60, 60), I got k=79.5. I thought k would be a constant that was the same for all equations, as in the force equation F=[k*q(1)*q(0)*r(hat)]/r^2 where k = 8.99x10^9.
Is k going to be constant, or will it change with different data?
and
How do I go about finding r(hat)?
and
What would be my units for k? (Nm^2/C^2)?