Rotation period of electron orbiting a proton

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Homework Help Overview

The problem involves an electron rotating around a proton in a circular orbit, with a specified radius. Participants are exploring the calculation of the rotation period based on the forces acting on the electron.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the application of force and acceleration equations, questioning the relationship between force and acceleration. There is also an exploration of how to calculate radial acceleration from the electric force and the mass of the electron.

Discussion Status

The discussion is ongoing, with participants raising questions about the correctness of the initial calculations and the assumptions made regarding the forces involved. Some guidance has been offered regarding the relationship between force and acceleration, but no consensus has been reached.

Contextual Notes

Participants are working under the constraints of the problem statement, which specifies the radius and the forces involved, while also considering the mass of the electron in their calculations.

SorenaJ
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Homework Statement


An electron is rotating around a proton (at rest) in a perfect circular orbit. If the radius of the orbit is r=10^-10 m, how long is the rotation period [hint: the radial acceleration is entirely due to the electric force]

k=9*10^9
q=1.6*10^-19

Homework Equations


1. F=(k*q^2)/r^2
2. arad=(angular velocity)^2*r

The Attempt at a Solution


I found the force by equaiton 1., and I got 2.3*10^-8 N ((9*10^9)(1.6*10^-19)^2))/((10^-10)^2)
I tried equation 2. to get (angular velocity)=sqrt(F/r) and got 15.2 rad/s
This means that it is 2.4 rev/s (by dividing by 2pi) and 0.41 seconds per orbital period.
That is like the world's slowest electron. Where did I go wrong?
 
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Is Force equal to acceleration? ... or is there something missing?
always use units, to avoid slip-ups like this.
 
Maybe not. It just says that the radial acceleration is entirely due to the electric force. To find the radial acceleration do I just need to say a=F/m?
 
well, the radial acceleration is caused entirely by the electric force, but it is mitigated via (spread thru-out) the electron mass
= .911×10-30 kg .
 

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