1. The problem statement, all variables and given/known data m' = G O^1/2 m^(-1/2) where m' = dm/dt. Find m by integrating this expression wrt to time (indefinite). 2. Relevant equations We have G = m'/m and O = constant/G^2 and m is a function of time m(t) 3. The attempt at a solution I know that integral of m'/m = ln m, so that means I can integrate the G part. I have tried to integrate O by taking the constant outside the integral, which leaves an integral of [1/(G^2)]^(1/2) or just [G^(-2)]^(1/2) or [(m'/m)^(-2)]^(1/2) I am not sure what form is easiest to work with, and have no idea how to start with this part! Could I use the substitution rule? I can't see how... The last part is an integral of m^(-1/2) which is 2m^(1/2). I also have no idea how to combine the three different parts together to give the final equation for the integral.