How can I find the relationship between E and r in this scenario?

[veronicak5678]

Homework Statement

How does E depend on r?

Homework Equations

E(r) = -dV/dr

v = -224.1r + 22.17

The Attempt at a Solution

dv/ dr = -224.1
E= 224.1

I need an equation that relates E and r, but r drops out when I differentiate...

 

[Pengwuino]

Was this potential just given to you?

 

[veronicak5678]

Potential? The equation with volts and radius (v = -224.1r + 22.17) is from my experiment, and the other (E = -dV/dr) is from my book.