# Electric potential along the x-axis

chicagobears34

## Homework Statement

The electric potential along the x-axis is V=100e^(−2x/m), where x is in meters.
Find Ex at x=1.0m and Ex at x=2.1m

V=Ed
Ex = dV/dx (?)

## The Attempt at a Solution

I took the derivative of V and got (-200/m)e^(-2x/m)
I don't know what m is and I'm just not sure how I can get an integer value for Ex at x=1.0m and 2.1m
EDIT===
I assumed m=1 and got the correct answer, don't understand what m is though