I have 3 ideas that i am stuck on, 1. If you have water displaced in newtons by a floating object, is the newtons displaced of oil or any other liquid, what is the equation to find this. I tried many equations with densities and bouyant forces, but i can't seem to get the right answer, i was maybe thinking since it is newtons of water replaced and oil replaced, not mass, that maybe the newtons of water replaced equals newtons of anything replaced. meaning if 100 N of water is displaced, 100 N of oil will be displaced by the same object, Am i correct in thinking this? 2. If you have a pendlum swinging from an elevator accelerating upwards, in taking the equation of pendlum's being period = 2 * pi * sqrt( L / g ), would you just add the acceleration to g by changing the part in the equation where g is to (g + a)? 3. I am trying to find the difference in periods of 2 planets with different masses, and different eccentricity, i have been hunting through my book for an hour, and another hour or 2 on the internet, and cannot find an equation that can give me these differences in periods. I was wondering what the impact of eccentricity is on a period. Is a bigger eccentricity going to cause a longer period? I cannot find this property anywhere. thanks.