- #1
mrxtothaz
- 14
- 0
Homework Statement
A test charge of +1.0x10^-6 C is 40cm from a charged sphere of 3.2x10^-3 C. How much work was required to move it there from a point 1.0x10^2 m away from the sphere?
Homework Equations
W = [tex]\Delta[/tex]E
W = Ee2 - Ee1
The Attempt at a Solution
Ee2 = (9.0x10^9)(1.0x10^-6)(3.2x10^-3)/(0.4)
= 72
Ee1 = (9.0x10^9)(1.0x10^-6)(3.2x10^-3)/(100)
=0.288
W = 72 - 0.288
= 71.7
= 72 (significant digits)
I'm pretty sure my approach is correct, but I'm not sure if I should reverse the distance variables, since I would imagine it takes negative work to bring two like charges closer.