 #1
hidemi
 208
 36
 Homework Statement:

A nonconducting sphere of radius 10 cm is charged uniformly with a density of 100 nC/m^3. What is the magnitude of the potential difference between the center and a point 4.0 cm away?
The answer is 3.0 V.
 Relevant Equations:
 V = kQ / r
I can use integral as attached to obtain the answer.
However, I wonder why I can not use " V = KQ / r " the get the correct answer.
Thanks.
However, I wonder why I can not use " V = KQ / r " the get the correct answer.
Thanks.