1. The problem statement, all variables and given/known data The earth orbits around the sun because it has angular momentum. If we stopped the earth in orbit and then let it fall straight towards the sun, how long would it take to reach the sun in seconds? Details and assumptions The mass of the sun is 2×10^30 kg. The mass of the earth is 6×10^24 kg. Newton's constant is 6.67×10^-11 Nm^2/kg^2. The earth is 149,600,000 km from the sun. You may treat the earth and sun as point masses. 2. Relevant equations F = GMsMe/R^2 center of mass R= (MsRs + MeRe)/(Ms + Me) d^2r/dt^2 = GMs/r^2 3. The attempt at a solution I realized that as these point masses get closer, the distance between them decreases resulting in a stronger force and thus a greater acceleration. d^2r/dt^2 = GMs/r^2 Since the Sun is also mutually attracted by the Earth and may move slightly, would using the center of mass help in any way? I'm not sure if this is the right way to approach this. Any help would be greatly appreciated.