- #1

zabumafu

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## Homework Statement

A very small sphere with positive charge 6.00uC is released from rest at a point 1.20cm from a very long line of uniform linear charge density 4.00uC/m.What is the kinetic energy of the sphere when it is 4.80cm from the line of charge if the only force on it is the force exerted by the line of charge?

## The Attempt at a Solution

Well we have not gone over this in class so I have no notes and can't seem to find a solution online. All I could think about doing was solving for the change in potential from the initial point at 1.2cm and since its at rest, all of the energy lost will be converted in kinetic.

So change in potential=-W/q with q being the charge of the particle.

Vi=initial potential

Vf=final potential

Vi=k(lamda)ln(xi)

=(8.99*10^9)(4.0*10^-6)ln(.012)

=-1.59*10^5

Vf=(8.99*10^-9)(4.0*10^-6)ln(.048)

=-1.09*10^5

dV=-4.985*10^4=-W/q

W=49.85*(6.0*10^-6)

W=K=.299J?

The answer is wrong but I have no other formulas to determine potential of a uniform line of charge.

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