Finding velocity in the Hall effect with given dimensions and voltage

[cookiemnstr510510]

Homework Statement

A metal strip 6.5cm long, 0.88cm wide, and 0.76cm thick moves with constant velocity, magnitude v along positive y-axis, through a magnetic field, B=1.2mT along positive z-axis. A potential difference of 3.9x10^-6V is measured between points x1 and x2 (as shown in halleffect.jpg). Determine the magnitude of the velocity, v.

Homework Equations

V_h=BVW

The Attempt at a Solution

info given:
length=6.5cm
width=0.88cm
thickness=0.76cm
B=1.2mT
V_h=3.9x10^-6V

V_h=BVW
V=(V_h)/BW→(3.9x1-^-6V)/((1.2x10^-3T)(0.88x10^-2m)→0.369m/s

Im wondering if I am missing something, this problem seems too easy.

Any insight would be appreciated!

Thanks

 

[gneill]

I dunno, seems to me that you got it in one. It's basically the same situation as a length of wire moving through a magnetic field with some velocity. See, for example: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/genwir2.html

Edit: I'm not sure why they're describing this as a Hall Effect problem. The Hall Effect usually involves a current moving through a slab of material subjected to an external magnetic field. But I suppose the charges in the moving block constitutes a current.