Circular Motion

[anthropos]

A bucket of water is swung in a vertical circle. Explain qualitatively why the water in the bucket does not fall out.

 

My model answer then explained that

 

If the speed of the rotation is high enough, the weight of the water alone in the bucket is not enough to provide for the centripetal force required. A force will be exerted by the bottom of the bucket on the water for the water in the bucket to continue to move in a circle. By Newton's third Law, the water pushes against the bottom of the bucket and thus stays in the bucket.

 

What does the bold text really mean? So what happens if the weight of teh water alone in the bucket is just enough? And if my speed is not high enough, the water flows of the bucket, and what does that mean? Sorry I am really confused. Can somebody clear my confusion?

 

Thanks

[swansont]

A bucket of water is swung in a vertical circle. Explain qualitatively why the water in the bucket does not fall out.

 

My model answer then explained that

 

If the speed of the rotation is high enough, the weight of the water alone in the bucket is not enough to provide for the centripetal force required. A force will be exerted by the bottom of the bucket on the water for the water in the bucket to continue to move in a circle. By Newton's third Law, the water pushes against the bottom of the bucket and thus stays in the bucket.

 

What does the bold text really mean? So what happens if the weight of teh water alone in the bucket is just enough? And if my speed is not high enough, the water flows of the bucket, and what does that mean? Sorry I am really confused. Can somebody clear my confusion?

 

Thanks

 

An object moving in a circle must have a force exerted on it to follow F = mv^2/r

 

If that force is the weight, i.e. v^2/r = g, then the bucket cannot be exerting and force. But what happens if the bucket is swung faster? Or slower?