1. The problem statement, all variables and given/known data Two particles with a similar charge are held at a distance of 3.2*10^-3 m and then released. The acceleration of the first particle is measured at 7.0 m/s^2, and for the second at 9.0 m?s^2. The mass of the first particle is 6.3*10^-7. What is the mass of the second particle? 2. Relevant equations F=ma F=G*m1*m2/r^2 3. The attempt at a solution F1=m1a1 F2=m2a2 (where F1 and F2 are the forces exerted by each particle respectively) F1 - F2 = G*m1*m2/r^2 (since the particles are similarly charged, they would have forces pointing in opposite directions) after substitution and making m2 the subject of the formula: m2 = (m1*a1*r^2)/(Gm1 + a2r^2) which gives: m2 = 4.31*10^-7 I am not so sure if the method I used is completely correct, can someone please tell me?