If the electric field strength between two parallel plates 1cm apart is 3.1kN/C, how much energy will be used by the electric field to move an electron (placed half way between the plates) 3mm nearer to the positively charged plate?
Work Done = 1/2V^2C
The Attempt at a Solution
I know that the answer to this question is 1.49x10^-18 J. I feel that I may be going about this question the complete wrong way but this is what I did:
I worked out the potential difference between the plates to be 31V by using the equation V=ED
V=(3.1x10^3)x(0.2x10^-2)-----> I got this value for D by taking away 3mm from the 5mm half way point between the plates.
I then subbed in the values that I know into the equation Work Done = 1/2V^2C
Work Done = 1/2 x 6.2^2 x (1.6x10^-19)
This gave me 3.08x10^-18.
I feel like I'm going the wrong way about this question. Hope someone can help and hope I've worded this well enough for you all to understand haha.