Hollow cylinder magnet making contact with the circuit

AI Thread Summary
The discussion revolves around the behavior of a circuit in relation to a cylinder magnet, focusing on two scenarios: the circuit moving downward while the magnet remains fixed, and the magnet moving upward while the circuit is stationary. The key question is how to express the force exerted on a charge in a fixed coordinate system when the magnetic field is uniform and the charge itself is not moving. The participant grapples with the application of the equation F = v x B, questioning how to interpret the force in the charge's frame of reference where its velocity is zero. The conversation highlights the complexities of understanding electromagnetic interactions from different perspectives.
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Homework Statement



mm.png


1. Circuit moves downward while cylinder magnet is fixed.

2. Cylinder magnet moves upward while circuit is fixed.

Gain emf in circuit.

Homework Equations



All those maxwell equations...
F=v x B

The Attempt at a Solution


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So first question is not that hard. Circuit moves in a static magnetic field. Okay. And I saw second question. Hmm. isn't it just relatively the same case as 1st one? But I've never thought of F=v x B in this way. I tried to see moving uniform magnetic field in fixed charge's coordinate. But it's just uniform magnetic field that doesn't change with time. And me, charge doesn't move at all from my perspective.

To sum up, my question is how does moving-uniform magnetic field is expressed in fixed charge's coordinate and how can I explain the forces that exerted upon this charge?
 

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The cylinders look different. One appears to have a hole drilled in side. Other one has a slot.
 
scottdave said:
The cylinders look different. One appears to have a hole drilled in side. Other one has a slot.

Yes, but that's not main concern for me. (Maybe I should just attached another adequate picture.)

My question is, there is a magnet and a charge which moves relative to each other. In magnet's coordinate, force exerted on charge can be easily expressed via F = v x B. But how can I explain this force in this charge's coordinate? Clearly v here is zero, and in above case magnetic field is also just uniform.
 
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