Register to reply

Magnetic Force Formula

by ccflyer
Tags: force, formula, magnetic
Share this thread:
ccflyer
#1
May18-05, 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
Phys.Org News Partner Science news on Phys.org
Scientists develop 'electronic nose' for rapid detection of C. diff infection
Why plants in the office make us more productive
Tesla Motors dealing as states play factory poker
HallsofIvy
#2
May19-05, 09:21 AM
Math
Emeritus
Sci Advisor
Thanks
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.
ccflyer
#3
May19-05, 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?

Pyrrhus
#4
May19-05, 10:31 PM
HW Helper
Pyrrhus's Avatar
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.
dextercioby
#5
May19-05, 11:11 PM
Sci Advisor
HW Helper
P: 11,927
Quote Quote by HallsofIvy
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.

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.
HallsofIvy
#6
May20-05, 05:16 AM
Math
Emeritus
Sci Advisor
Thanks
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. "
dextercioby
#7
May20-05, 07:44 AM
Sci Advisor
HW Helper
P: 11,927
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.


Register to reply

Related Discussions
I got the formula, what does the angle effect? Net Magnetic force Introductory Physics Homework 4
Magnetic force, finding angle between velocity and magnetic field Introductory Physics Homework 4
Magnetic lines of force and magnetic flux Classical Physics 9
Formula derivation - Magnetic induction in spinning discs - Magnetic braking Introductory Physics Homework 0
Need help for a prove about magnetic field and magnetic force Classical Physics 3