A very small sphere with positive charge 5.00uC is released from rest at a point 1.20cm from a very long line of uniform linear charge density 3.00 uC/m.

What is the kinetic energy of the sphere when it is 4.50cm from the line of charge if the only force on it is the force exerted by the line of charge?

Question

A very small sphere with positive charge  5.00uC  is released from rest at a point 1.20cm  from a very long line of uniform linear charge density 3.00 uC/m.

What is the kinetic energy of the sphere when it is 4.50cm  from the line of charge if the only force on it is the force exerted by the line of charge?

jamesj · Answer

Ok, so what what's the electric field from a (essentially) infinite uniformly charged line? Use that to find the force on the sphere and from that, calculate the work integral to find the kinetic energy.