HELP! Electricity/Magnetism Physics Problem

[UNLTuba]

I'm taking the second semester of a non-calculus based physics class (mostly cuz it's been four years since I've taken calc), and have a question on one of the assigned problems. Being that it's due tomorrow, I can't exactly go in for help any time before then... Anyway, here it is:

The figure below (seen here) shows a vertically orientated loop in a 1T horizontal magnetic field. The loop is 20cm x 20cm, has a mass of 10g, and a resistance of 0.01ohms, and is halfway through the field. The loop is released from rest.
a) Will the loop fall with constant speed or constant acceleration?
b) How long will it take the loop to leave the field? How does this compare to the time it would take the loop to fall the same distance in the absence of a field?

The magnetic force on the loop ends up being perpendicular to the field, pointing towards you if the field is pointing directly right. That was easy enough to figure out using the good ole right hand rules. I'm wondering if that component of force affects the loops motion in the y-direction being that the force acts in the x-direction. Anyway - any insight you have to this problem would be greatly appreciated. Thanks in advance!

- Eric

 

[UNLTuba]

No one?

 

[TuxDave]

Oomph.... *EE Grad student to the rescue!*

Umm... so constant velocity vs constant speed. Ok... this is my best bet. So the ring is falling, so there will be a change in magnetic field enclosed in the loop. That will create an EMF. Given EMF and the loop's resistance, you can calculate its current. Given the current and the strength of the magnetic field, it'll induce a force upwards. If that force upward equals the force of gravity, then it'll be constant velocity.

edit: in more detail, the induced current should be flowing towards you on the top wire. As for what the velocity should be? Keep it in terms of v, maybe you can find the terminal velocity of the falling wire.