Deflection of an electron due to gravity.

AI Thread Summary
Gravity is negligible in J.J. Thomson's experiment because the magnetic field applied perpendicular to the electric field compensates for any gravitational deflection. The deflection due to gravity is calculated using the velocity of the electron, time, distance, and the angle of deflection. The attempt to solve for deflection yields a very small value, close to the book's answer of 10^-15 m, but the calculations do not match perfectly. The discussion also clarifies that general relativity is not applicable here due to the low speed of the electrons involved. Overall, the focus remains on understanding the minimal impact of gravity in this context.
theinfojunkie
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Homework Statement


There are two parts to the question.
A)Why is gravity not important during JJ Thomsons experiment?
b)what is the deflection due to gravity?
Given variables.
In a thomson spectromoter set at 10^4 (V/m). deflection without the magnetic field applied equals .10 radians over a L of .050 m.
Speed of electron with magnetic field applied is 2.9x10^7 m/s.
Strength of Magnetic field is 3.4x10^-4 T.

Homework Equations


I don't know what they are...

The Attempt at a Solution


A) in the experiment the effects of gravity were negated by the application of a magnetic field perpendicular to that of the electric field, to help over come any deflection caused by gravity.
B) I really don't know how to go about this.
EDIT:
I thought about it a little more...would I just be using the velocity, time distance and deflection angle to solve this??
Like...a particle fired at a zero degree angle?
 
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Alright so as far as I have it figured.
v(y) = gt

then take v(y)/v(x) and take the inverse tan of it to get the answer.
It gives the angle of deflection in radians. The answer I got does not match that of the book but is close enough. It's a very small number.
the answer the book was looking for was 10^-15 m.

Now if it's done by taking .5(at^2) i get another answer, but the order is wrong. It comes out to something like 1.7x10^-17 or something or other. Any ideas what exactly they did??
 
theinfojunkie said:
Any ideas what exactly they did??
is it a GR problem or wat do you need to use GR Action or What?
 
General Relatvity??
No it is not. The speed is to slow.
 
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