(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

So my text book has a lot of example of conducting rails moving horizontally with unknown variables of F and B, but how would you approach a problem that has such a device pointed vertically with the moving bar droping? lets say R and B are known and we need to find I(current) sufficient to counteract gravity so it doesn't accelerate past a velocity required to generate that current.

2. Relevant equations

Fb=qv x B

R = delta V/I

Fg = mg (call the mass of the rod m )

I = p/delta V

3. The attempt at a solution

I played with it, but not sure if Im right.The part im stuck on is what relation of the magnetic field do I set equal to Fg

is it Fg= qV x B

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# Homework Help: Conducting rail ciruit, against gravity

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