Magnetic fields and current flows

[liz_p88]

Homework Statement

A 2.50 meter long copper rod has a mass of 0.25 kilograms. A magnetic field of 0.15 Teslas is oriented horizontally from south to north. a.) What is the minimum current in the rod that would allow it to "levitate" in this magnetic field? b.) What is the direction of the current in the wire?

Homework Equations

F = mg
F = ILB
ILB = mg

The Attempt at a Solution

I = mg/(LB)

(.25kg)(9.8m/s^2)/(2.5m)(.15T) = 6.533 A, East

I'm not sure if I did this correctly

 

[supratim1]

yes you are correct.

 

[liz_p88]

Thank you! I doubt myself so much. I have to work so hard to understand these concepts and formulas

 

[supratim1]

yes, work hard and you will gain confidence.

 

[rwisz]

, but assuming all the given information is accurate, your solution seems to be correct. The direction of the current in the wire would indeed be east, as determined by the right-hand rule for magnetic fields. It is important to note that this calculation is only an approximation and there may be other factors at play that could affect the actual minimum current needed for levitation. Additionally, it would be helpful to provide units for your final answer (6.533 A) to make it more clear. Overall, your solution is a good starting point for further investigation and experimentation.