Electron Motion in a Long Solenoid

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In the discussion about electron motion in a long solenoid, a problem involves calculating the current based on an electron's circular motion within the solenoid. The solenoid has 100 turns/cm, and the electron moves at a speed of 0.048c with a radius of 0.022 cm. The initial calculation for current yielded an incorrect value due to using the mass of a proton instead of an electron. After correcting the mass, the calculations aligned with the expected results. The importance of using the correct particle mass in physics equations is emphasized.
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Homework Statement



A long solenoid has 100 turns/cm and carries a current i. An electron moves within the solenoid in a circle of radius 0.022 cm perpendicular to the axis of the solenoid. The speed of the electron is 0.048c (c is the speed of light).

Homework Equations



f = m*v^2/r = q*v*B
B of a solenoid = u*n*I
where n = number of turns per meter
u = 4*pi*10^7


The Attempt at a Solution



so B = mv/(r*q) = u*n*I
I = mv/(r*q*u*n)
I = 5436.9 is not correct
 
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your working looks fine to me... But I got a different value for the current when I plugged the numbers in. Maybe that's where the problem is.
 
I was using the mass of a proton instead of an electron. replugged the numbers, and it works now!
thanks!
 

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