- #1
kaspis245
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Homework Statement
A frame is made of two firm wires of length ##h## and a rod of length ##l## and mass ##m##. This frame can rotate around horizontal axis in uniform magnetic field ##B##. In a short amount of time ##τ## a current ##I## passes through the frame. What is the maximum angle that the frame can make with its equilibrium state? Consider that in time ##τ## the frame moved very little.
Homework Equations
##F=Bqv##
The Attempt at a Solution
Let's denote the total length of the frame by ##L## so that the length is ##L=l+2h##.
The rod is affected by two forces ##mg## and ##F=Bqv=Bq\frac{L}{τ}=IBL##.
The rod is moving because it is affected by a force. This force has horizontal and vertical components.
Ox: ##ILB+mgsinα##
Oy: ##mgcosα-IBLsinα##
So ##F=\sqrt{(ILB+mgsinα)^2+(mgcosα-IBLsinα)^2}##.
Now, I don't know if what I wrote above is true. I've been making a lot of sketches and everything seems correct. But if we look into the first drawing, we can easily see that the sum of forces ##mg## and ##IBL## is ##F=\sqrt{(ILB)^2+(mg)^2}##. I don't know which expression is correct. Also, I don't know if I'm going the right way. Please help.