Potential difference between Bird's Feet?

AI Thread Summary
The discussion centers on calculating the potential difference between a bird's feet while perched on a high-voltage power line. The bird's feet are 2.0 cm apart, and the wire carries a current of 160 A. Participants suggest using the formula for resistance, R = ρL/A, where ρ is the resistivity of aluminum, L is the distance between the feet, and A is the cross-sectional area of the wire. The relationship I = V/R is highlighted as a method to find the potential difference once resistance is determined. The conversation emphasizes the importance of correctly calculating resistance to apply Ohm's Law effectively.
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Homework Statement



A bird sits on a high-voltage power line with its feet 2.0 cm apart. The wire is made from aluminum, is 3.0 cm in diameter, and carries a current of 160 A. What is the potential difference between the bird's feet?

Homework Equations



I=neAv

Where I is current, n is electrons per volume, A is cross sectional area, v is drift velocity.

V=E*D

The Attempt at a Solution



My answer is going to have units of J/C, and the cross sectional area of the wire is 1/4*Pi*(3cm)^2.

I don't know where to proceed from here.
 
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Is there anyway you can find the resistance of the wire, maybe using the area and the fact that it's made out of Aluminum?
 
G01 said:
Is there anyway you can find the resistance of the wire, maybe using the area and the fact that it's made out of Aluminum?

Thanks for helping me. Yes, I can find the resistance:

R = p*L/A
= p * (2 cm)/A

Where p for Al is 2.82E-8 ohms*m, A is the cross sectional area, 1/4*Pi*(3 cm)^2

Where to go from here?

Edit:

Oh wait a second, I = V/R so I*R=V. Is that it?
 
Last edited:
mrlucky0 said:
Thanks for helping me. Yes, I can find the resistance:

R = p*L/A
= p * (2 cm)/A

Where p for Al is 2.82E-8 ohms*m, A is the cross sectional area, 1/4*Pi*(3 cm)^2

Where to go from here?

Edit:

Oh wait a second, I = V/R so I*R=V. Is that it?

You're a good part of the way there. We want to know the potential difference between the bird's feet. You have the current given in the problem. How would you find the resistance involved?
 
mrlucky0 said:
Thanks for helping me. Yes, I can find the resistance:

R = p*L/A
= p * (2 cm)/A

Where p for Al is 2.82E-8 ohms*m, A is the cross sectional area, 1/4*Pi*(3 cm)^2

Where to go from here?

Edit:

Oh wait a second, I = V/R so I*R=V. Is that it?

Yes, once you calculate the resistance, Ohm's Law would be the way to go.
 
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