1. The problem statement, all variables and given/known data A point charge Q resides at the origin. A particle of mass 0.005 kg carries a charge of 2 µC. The particle is released from rest at x=3 m. Its kinetic energy as it passes x=0.5 m is 0.28 J. The Coulomb constance is 8.99x10^9 N*m^2/C^2. Find the charge Q. Answer in units of µC. 2. Relevant equations Conservation of energy: PE_f + KE_f = PE_i + KE_i 3. The attempt at a solution KE_i = 0 (starts from rest) PE_i = kqQ/xi = kqQ/3 KE_f = .28 j PE_f = kqQ/.5 kqQ[(1/.5) - (1/3)] = - .28 (8.99 x 10^9)(2)Q[1.66667] = -.28 Q = -9.3437152 x 10^-12 µC What am I missing or doing wrong?