Context: a metal sphere swings in circular motion about a horizontal bar, in which the sphere is connected to the bar by a rod.
Why is the tension in the rod equal to the centripetal force provided by the rod subtract the weight of the sphere, i don't think there should be tension in the rod in the first place because at the instant the rod is at the top the sphere is perfectly following the circular path so it doesn't need a centripetal force to keep it on its path at that instant.
Please help 🙂