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An infinitely long line of charge has a linear charge density of 8.00×10−12 C/m. A proton is a distance of 17.5 cm from the line and moving directly toward the line with a speed of 2700 m/s.

How close does the proton get to the line of charge?

Use 1.60×10−19 C for the magnitude of the charge on an electron, 1.67×10−27 kg for the mass of a proton, and 8.85×10−12 F/m for the permittivity of free space

**From my notes and working etc. I've got:**

E = lambda/2*pi*epsilon*r (where lambda = charge per unit length and epsilon = permittivity of free space)

F = E * q (where q = the charge of the proton, -1.60*10^-19, as apparently defined by the question)

I've used the F calculated to get acceleration by

a = F/m (where m = mass of proton)

I get a value of -7.88*10^7

I then use the linear acceleration formula v^2 = u^2 + 2*a*s to try and calculate s.

I get 0.04627... (4.63*10^-2)

Apparently this is incorrect however. Can anyone see where I'm messing up?