# Homework Help: Spherical Charge

1. Sep 17, 2013

### stumpoman

1. The problem statement, all variables and given/known data
I have a question about notation. My professor posted an older practice test with some different notation techniques than I am used to.

"Sphere Charge
Find the electric field 2.5 m from the center of a region of space with a charge density given by ro=5.5 E-15 R**(2.3)"

I understand most of it but am unsure what the R**(2.3) means.

2. Relevant equations

E = kQ/r^2
ρ = 5.5 E-15

3. The attempt at a solution

I assume the R**(2.3) has something to do with the volume of the sphere but other than that I have nothing.

Attached is a screenshot of the question.

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2. Sep 17, 2013

### Dick

'**' is Fortran talk for power. It's just $R^{2.3}$. It's giving the charge density as a function of distance from the center of the sphere. You need to integrate that over the sphere to get total charge.