Hi, I'm making a game and could do with a hand working out how to simulate the main element of it. I'm sure I should be able to work this out, it seems relativly simple, but I'm so out of practice the solutions eluding me. I need to simulate two point masses connected by a massless string or rod (it doesn't matter which; so whichever's easiest). I'm fine with the basics of moving them about but can't figure out how to calculate the force exerted on each mass by the string/rod. I guess it'd be derived from the velocities of the opposite mass but further than that I'm stuck. Can anyone help?