Calculating Potential Difference for a Bird on a Power Line

[Wnt2bsleepin]

A bird, whose feet are 3cm apart, perches on a bare "High tension" power line carrying a
current of 720A. If the wire has a resistance of 80μΩ/m, calculate the potential difference between the bird's feet. Do you think the bird will be electrocuted?



r = p * (L/A)



I have the problem set up as (8 * 10^-5Ω/m) * (.03m/A). I don't know what to put for the area since the cross section hasn't been given. I am aware that the bird should not be electrocuted since its potential is the same as the wire, so there should be no current.

 

[gneill]

A bird, whose feet are 3cm apart, perches on a bare "High tension" power line carrying a
current of 720A. If the wire has a resistance of 80μΩ/m, calculate the potential difference between the bird's feet. Do you think the bird will be electrocuted?
r = p * (L/A)
I have the problem set up as (8 * 10^-5Ω/m) * (.03m/A). I don't know what to put for the area since the cross section hasn't been given. I am aware that the bird should not be electrocuted since its potential is the same as the wire, so there should be no current.

Hi Wnt2bsleepin, Welcome to Physics Forums.

Note that the resistivity of the wire is given to you in units of Ohms per-meter. So the cross sectional area is already factored in.

 

[Wnt2bsleepin]

Thanks, then all I have to do is multiply by the distance and I should get what I want.