1. The problem statement, all variables and given/known data We have two particles, m1 and m2 at positions x1 and x2, and we want to come up with the equation of motion of particle m1 due to the gravitational field of m2 (position of m1 as a function of time). 2. Relevant equations F=Gm1m2/r^2 F=ma 3. The attempt at a solution m1a=-Gm1m2/r^2 a=-Gm2/(x2-x1)^2 d^2x1/dt^2=-Gm2/(x2-x1)^2 Now, I don't know how to solve this. Any help will by appreciated.