Homework Help: Electric Fields of straight wire

1. The problem statement, all variables and given/known data
A very long, straight wire has charge per unit length 1.47×10^10

At what distance from the wire is the electric field magnitude equal to 2.57 N/C


2. Relevant equations

E = lambda / (2*pi*E_o*r)

E_o = 8.85*10^-9


3. The attempt at a solution

2*pi*E_o*E / lambda = r

Is this correct so far?

 

r = 2*pi*(8.85*10^-9)*(2.57) / (1.47*10^-10)

I'm not sure if lambda is represented correctly and is E just 2.57 or should it be 10^(something)

 

I wasn't sure if lambda = 1.47*10^-10

 

Thats what I had before 1.47 x 10^-10

 

The original question was if lambda = 1.47 x 10^-10.

You said yes, so I just wanted to make sure.

 

2*pi*(8.85*10^-9)*(2.57) / (1.47*10^-10) = r

This evaluated to:
r = 972

The online program says I'm off by an additive constant??

 

2* (1/4*pi* 8.85*10^-9) * (1.47*10^-10) / 2.57

= 1.03×10−3

Still says I'm off by a additive constant.

 

I need to be more careful from paper to online input. I have so much scratch work, some how I changed the epsilon value =[