- #1

sfdevil

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## Homework Statement

A square loop made of wire with negligible resistance is placed on a horizontal frictionless table. The mass of the loop is m and the length of each side is b. a nonuniform vertical magnetic field B=B0(1+kx) exists in the region, where B0 and k are constants. The loo is given a quick push with initial velocity v along x-axis. The loop stops after a time interval T. Find the inductance of the loop.

## Homework Equations

emf(ind) = -L*dI/dT

U=1/2*L*I^2

emf= -delta flux/delta t

## The Attempt at a Solution

well, I am sort of in a loss for this one.

I tried to get the induced emf by finding dflux/dt:

flux

=integral ( B0*(1+kx) * b dX )

= b*B0*(b*2*k*x+b^2*k+2*b)/2

change of flux in regards with time = dphi/dx * dx/dt

= b^2*k*B0*v (because velocity= dx/dt)

so emf is b^2*k*B0

now I am not sure what to do, since the resistance is negligble and i can't find the current from it...

also the whole time interval thing, where does it come into play (kinematics ?)

and should I use conservation of energy here ?

1/2 * m * v^2 = 1/2 * L * I^2 ? for some reason I don't think its the right way

just thoroughly confused with this one. please help !