An infinitely long line of charge has linear charge density 4.00×10-12 C/m . A p
ID: 2051024 • Letter: A
Question
An infinitely long line of charge has linear charge density 4.00×10-12 C/m . A proton (mass 1.67×10^27 kg , charge ) is 14.0 cm from the line and moving directly toward the line at 2500 m/s .the proton’s initial kinetic energy.
is K =5.219×10^-21 J
my question is how to go about finding this answer.
How close does the proton get to the line of charge?
The answer is r = 8.89×10^-2 m -- THIS IS THE ANSWER PROVIDED BY MASTERING PHYSICS
but i dont understand how they got the answer.
please help and show steps.
Explanation / Answer
Find the electric field around the conductor. (use Gauss' law). Then integrate to get the potential energy of the proton as a function of the distance to the conductor(kq/r)