An electron of mass 9.1E-31 kg is released from rest at a distance of 7.1 E-10 m from a fixed electron. The force on the movable electron is given by the function F = 2.3E-28/r^2, where r is the distance between the electrons. Find the maximum velocity (in meters/second) of the moving electron after release.

^ we're supposed to use mechanical energy theorums to solve this problem

2 answers

I assume you are a calculus person.

work done on electron= final KE of electron

and from final KE, you calaculate the velocity. What is work done on the electron?

work= intgeral force dot dx integrated from original distance to final distance.

Now the final distance here is not specifed, and velocity will depend on that. If you are unsure, let the final distance be rfinal.

If you use zero as the final distance between the electrons, you complicate the integral as you will see.

You can also use potential theory here, I am not so certain you have had that yet.
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