Re: E=F/q=vB Magnetic Force does not work on the charge

On Jul 13, 4:36 am, "T.M. Sommers" <t...@xxxxxx> wrote:
gu...@xxxxxxxxxxx wrote:
On Jul 12, 5:47 pm, "T.M. Sommers" <t...@xxxxxx> wrote:
gu...@xxxxxxxxxxx wrote:

Model: A wire moving perpendicularly through a N&S magnetic field

Quote:"It is ****ERRONEOUS**** to think that the magnetic force does
work on the charges to produce an EMF. We recall that the magnetic
force is PERPENDICULAR to the velocity and hence to the displacement
of the charge deltaW= F deltaS Cos(angle) where deltaS = displacement
and in this case angle = 90 degrees therefore NO WORK IS DONE BY THE
*****MAGNETIC FORCE********."

If one cannot figure out that the reverse is also true and that a
magnetic force also does not affect a perpendicularly moving charge,
absolutely no interaction occurs.

Your quotation does not say there is no interaction, it says no
work is done. Work is the integral of the vector dot product of
the force and the differential displacment. Since the force and
the displacement (which is parallel to the velocity) are always
perpendicular, the dot product is always zero, and no work is
done. If work were done, the speed of the charge would have to
change, and it does not.

Work is a bad thing.

Not if you want a paycheck.

W= F d ,

Not exactly. F and d are vectors, and W is the dot product.

if F = zero not only W = zero

Yes.

but d also
= zero,

No. Things can move without a force acting on them. Remember
Newton's first law?

d as in net displacement (as opposed to distance)

power/energy consumption is a more appropriate term that
should have been used?

Power is energy per unit time.

When work is done, kinetic energy does change. In the moving
charge in a magnetic field situation under discussion, the
charge's speed does not change, which is another indication that
no work is done.

If you wish to live and breed by the physics books statement I just
posted:

If the wire is parallel with the magnetic field cos (0) = 1 thus work
is no longer zero and yet no EMF will be produced. (statement says no
EMF because work = zero, work = zero because cos(90) = 0.



--
Thomas M. Sommers -- t...@xxxxxx -- AB2SB- Hide quoted text -

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