Electric potential along the x-axis

samedi 30 novembre 2013

1. The problem statement, all variables and given/known data

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

2. Relevant equations

V=Ed

Ex = dV/dx (?)

3. 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