Re: Experimental verification of the relativity theory

[Bob LaMontagne <rlamont@POSTOFFICE.PROVIDENCE.EDU>]

Bernard Cleyet wrote:

> not certain I understand your question.   I assume an increase in mass will require
> a greater B to deflect the electrons vertically (up and down WRT the kinescope face
> plate) and horiz. (right and left).   Anyone know why after a few years
> electrostatic deflection was replaced by magnetic in TV sets.  (I've only seen one
> that used electrostatic (deflection plates) deflection.  It also had a full 13
> channels! (included channel one).

You basically answered it with your comments about vertical and horizontal. It's just a
pet peeve of mine that textbooks glibly assign a relativistic mass, m/sqrt(1-v2/c2), to
a moving particle, implying that it is more difficult to accelerate because of this
increased mass. What they don't point out to the student is that this is true only in
the case you mention where the force is perpendicular to the motion (transverse mass).
When the force is parallel to the motion, the inertial aspect of the mass becomes
m/(1-v2/c2)^(3/2) (longitudinal mass), if one insists on using the F=ma version of
Newton's 2nd law. This would correspond to the motion produced from the large
electrical voltage accelerating the electron to the screen itself. The 5% correction
you mentioned would then be approximately a 15% correction to the mass. Of course if
the F=dp/dt version of Newton's Law is used this all becomes irrelevant.

Bob at PC