- #1
Crush1986
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- 10
Homework Statement
Side Flash. Part of a bolt of lightning jumps through distance d in air and then travels through the person ( who has negligible resistance relative to that of air because of the highly conducting salty fluids within the body). The rest of the current travels through air alongside the tree, for a distance h. If d/h = .400 and the total current is I = 5000A, what is the current through the person?
https://imagizer.imageshack.us/v2/1920x893q90/633/IF9c3g.png
Homework Equations
R= rho* L/A
The Attempt at a Solution
W[/B]hile attempting this problem I could see that the person and the air along the tree form a circuit that is in parallel. So the voltage across the person and the air along the tree is the same. So the resistance of one side of the circuit multiplied by it's current will equal the other side of the circuit's resistance multiplied by it's current. I also know that the total current of 5000A will be equal to the amperage that flows through the person and along the tree.
I became stuck here though. Knowing that the resistance equation rho*L/A was probably going to play a part. I found a solution manual that equated the current of one side multiplied by d equals the current of the other side multiplied by h.
After reworking the equation you have that the larger current through the person is 5000/1.4 and the other current is simple to find from there.
Can anyone give me some insight as to how you make the jump to knowing that i1*h = i2*d is something that is valid to do?
Thank you in advance and I apologize for the ugly typing and equations, I was looking into latex but it just all seemed so overwhelming.
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