For this question, I have solved letters a, b and c. I'm stuck at letter d.(adsbygoogle = window.adsbygoogle || []).push({});

1. The problem statement, all variables and given/known data

Two point charges ql = +2.40 nC and q2 = -6.50 nC are 0.100 m apart. Point A is midway between them; point B is 0.050 m from ql and 0.060 m from q2 (Fig). Take the electric potential to be zero at infinity. Find

(a) The potential at point A;

(b) The potential at point B;

(c) The work done by the electric field on a charge of 2.50 nC that travels from point B to point A.

(d) The speed of the 2.50 nC when it reaches point A, if it starts from rest at point B

2. Relevant equations

KE = 1/2 m v^{2}?

3. The attempt at a solution

I have solved a, b and c

a) V_{A}= -737 V

b) V_{B}= -704 V

c) W_{B->A}= +8.2 x 10^{-8}J

Now I'm stuck at letter D, how do i find the speed? I assume that I might need the equation of KE = 1/2 m v^{2}.. But I dont know how to do it.

What I did was to put +8.2 x 10^{-8}J as my KE. However, I do not have a mass, so how do I do this?

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# Homework Help: Find the speed of the charge

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