i'm ashamed, that i never understand this, eventhough i'm studying quantum mechanics.... so..... why is there "weightlessness" on the top of a verticle circular motion? ie, if a plane if flying in verticle circles, why is there weightlessness while on the top of a circular path? i mean, if it's weightlessness, that means that the wieght of the object is cancelled by a force equal and opposite, leaing to no net force, not change in interia, and therefore weightlessness.... however, that's not the case.....? on the top of a circlar motion/path, the wieght points down to earth, whilst the centripital force is also pointing downwards.... wouldn't that make the person to feel even more force applied downwards? the answers always "the weight = centriplital force" but i don't get how does that mean "weightlessness"