- #1

- 50

- 0

## Homework Statement

A 33 -cm-diameter conducting sphere is charged to 457 V (relative to a point an infinite distance from the sphere where the potential is zero).

a. What is the surface charge density σ?

## Homework Equations

Surface Area= 4(pi)r^2

Surface Charge Density= Q/A

V=kQ/r

## The Attempt at a Solution

So initially I found the surface area (it's 3421.1944 cm^2) and then divided the electric potential by that. This is obviously wrong.

Then, I used the formula for electric potential and solved for Q to get the charge of the sphere. I got 8.388x10^-9 C. I think I may have done something wrong because my units didn't cancel out quite right, but I didn't think too much about it. I then plugged this into my formula for surface charge density, and got 2.452x10^-10 C/m^2. My answer is supposed to be in uC/m^2 so I multiplied the answer by 10^6 and got 2.452x10^-4 uC/m^2.

I put this into the answer box, and it is wrong.

So thenI thought maybe I plugged in the wrong distance before (I used the radius of the sphere and not the diameter though i'm sure the radius is correct) and did the same as above, and ended up with 4.412x10^-3 uC/m^2.

So right now, I'm simply at a loss as for what I'm doing wrong.

I'd like to note that I'm in an algebra-based physics class for a reason- calculus is lost on me, I'm sorry.