help on electric potential problem

[supermenscher]

I have done this problem over and over and keep getting the wrong answer. What is the electric potential a distance of 3.0E-15m away from a proton.

I used V=kQ/r and got 4.8E-25 V, and it says the answer is wrong.

The second part of the question asks what is the potential energy of a system that consists of 2 protons 3.0E-15m apart.

I used V=k(1.6*10E-19)^2/r and got 7.68E-44J and webassign told me it was wrong. Can anyone help

[chroot]

Looks like you're just making arithmetic errors:

http://www.google.com/search?num=30&hl=en&lr=&ie=UTF-8&safe=off&c2coff=1&q=%281%2F%284*pi*epsilon_0%29%29+*+%281.6*10%5E-19+C%29+%2F+%283.0*10%5E-15+m%29&btnG=Search

- Warren

[supermenscher]

Thank you so much