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Magnetic Force Formula 
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#1
May1805, 10:19 PM

P: 6

Hi everyone, I am trying to learn about electromagnets for a project I am working on and I need to know how much magnetic force (in Teslas) that I would need to lift a given weight. Would anyone be able to point out a formula that I would be able to use?
Any help would be greatly appreciated! ccflyer 


#2
May1905, 09:21 AM

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PF Gold
P: 39,564

First, a Tesla is NOT a unit of magnetic force it is a unit of magnetic flux density the flux density that will result in a 1 Newton force acting on a one coulomb charge moving at one meter per second perpendicular to the magnetic flux direction.
So no one can tell you "how many Teslas" you need to lift a given weight it depends on much more than weight. Of course, you would start by expressing your weight in Newtons that's the force you need. Now you would need to figure in the magnetic properties of the material you are lifting that's going to be the hard part. The same magnetic field will result in different forces on different kinds of metals. 


#3
May1905, 10:22 PM

P: 6

alright, I get what you are saying, and I guess that makes sense, but would you be able to point me in the direction of a formula?



#4
May1905, 10:31 PM

HW Helper
P: 2,277

Magnetic Force Formula
Well magnetic force is defined as
[tex] \vec{F}_{b} = q \vec{v} \times \vec{B} [/tex] where q is the charge, B is the magnetic field, and v is the velocity of the charge. 


#5
May1905, 11:11 PM

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No,no,big confusion.The Tesla (apud Nicolo Tesla) is a unit for MAGNETIC FIELD INDUCTION,commonly noted by [itex] \vec{B} [/itex],which is a pseudovector. See post #7. Daniel. 


#6
May2005, 05:16 AM

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PF Gold
P: 39,564

This is what I found at http://www.answers.com/topic/tesla
"The unit of magnetic flux density in the International System of Units, equal to the magnitude of the magnetic field vector necessary to produce a force of one newton on a charge of one coulomb moving perpendicular to the direction of the magnetic field vector with a velocity of one meter per second. It is equivalent to one weber per square meter. " 


#7
May2005, 07:44 AM

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It's not called "magnetic flux density",but "magnetic induction".
[tex] \Phi_{mag}=:\iint_{S} \vec{B}\cdot d\vec{S} [/tex] ,so indeed the magnetic induction is the magnetic flux density.But the first name is the correct SI one. Daniel. 


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