1. The problem statement, all variables and given/known data Two protons are held fixed at a distance of 3 angstroms (3 x 10-10 m) from one another. The protons have a charge of +1.6 x 10-19 C. After they are released they repel each other and fly apart and each acquires some kinetic energy. What is the final total kinetic energy of the two particles when they are at a large distance from each other? 2. Relevant equations Potential Electric Energy= (1/4pie)*q1q2/r Ki+Ui=Kf+Uf 3. The attempt at a solution 3A * (3e-10m/1 A) = 9e-10m Ue=(9e9 Nm^2/C^2)(1.6e-19C)(1.6e-19C)/(9e-10m)= 2.56e-19 Nm And I know that as r goes to infinity, potential energy goes to 0 thus 0+Ui=Kf+0 2.56e-19J=Kf But the answer is 7.7e-19, what i am doing wrong, what step am I missing thank you!