Rotation period of electron orbiting a proton

AI Thread Summary
The discussion centers on calculating the rotation period of an electron orbiting a proton, with a given radius of 10^-10 m. The electric force acting on the electron is calculated using Coulomb's law, resulting in a force of 2.3*10^-8 N. The angular velocity is derived from the relationship between force and radius, yielding a value of 15.2 rad/s, which translates to an orbital period of approximately 0.41 seconds. Participants question whether the force equals acceleration and discuss the role of the electron's mass in determining radial acceleration. The conversation emphasizes the importance of careful unit usage in 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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