Question

A bucket of water can be whirled in a vertical circle without water spilling out. Explain why?

Answer 1

For water to remain in the bucket, there must be a centripetal force forcing the water to move in a circle with the bucket. Centripetal force gets larger with greater velocity. The FC comes from tension in the persons arm and the weight of the water. If the velocity isn't great enough the water will spill out.