How Does a Hard Disc Drive's Magnetic Field Affect an Electron's Motion?

AI Thread Summary
The discussion centers on calculating the Lorentz force acting on an electron in a hard disk drive's magnetic field of 95mT, with the disk rotating at 7200 rpm. The user attempted to solve the problem using the equations for circular motion and velocity but arrived at an unrealistic force value of 4.6 * 10^-34 Newton. There is confusion regarding the correct formula for the Lorentz force, which is essential for determining the force exerted by the magnetic field on the moving electron. Clarification on the appropriate approach and equations is sought to accurately compute the Lorentz force and compare it to the electron's weight. Understanding the correct application of the Lorentz force formula is crucial for resolving the user's issue.
Zimtstange
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Homework Statement


I don't quite understand the following question, i get a very unrealistic result...

The write head of a hard disc drive produces a magnetic field of 95mT. The disc has a radius of 3.5 inches and rotates at 7200 rpm (rotations per minute). Calculate the Lorentz force acting on an electron near the edge of the disc.
Compare the result to the electron's weight.

Homework Equations



f = v/(2*\prod*r)

F= (m*v^2)/r

The Attempt at a Solution



i tried to solve it with this two equations but i got 4.6 * 10^-34 Newton for the Lorentzforce... :confused:

can somebody help me?
 
Physics news on Phys.org
What's the formula for Lorentz force? (The force a magnetic field exerts on a moving charge.)
 

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