# Homework Help: Bucket in a circle question

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1. Oct 17, 2015

### AAAA

1. The problem statement, all variables and given/known data
I was watching a video on centripetal forces, and at one point in the video, the instructor poses a question where he shows a bucket filled with water which requires an Fnet of 3N towards the center to keep the water in the bucket.
At one point in the video (please seek to 6:09)

he says that the water will fall out of the bucket at the top because there is an Fg of 4N, but if there is no force of tension and the bucket and water are both accelerating at 9.8m/s/s (assuming down is +ve) then will the bucket not stay in the water?

2. Relevant equations
N/A

Last edited: Oct 17, 2015
2. Oct 17, 2015

### paisiello2

Well, presumably when the bucket hits the ground the water will not stay in the bucket.

3. Oct 17, 2015

### AAAA

I guess so, but while the bucket is in the air, it should be accelerating downwards w/ the water @ 9.8m/s/s, no? Meaning the water stays in the bucket?

4. Oct 17, 2015

### haruspex

You make an interesting point, but there are some practical considerations.
If the bucket is at least half full, the surface water will be closer to the axis of rotation than will the bucket's CoM. This means it requires less centripetal acceleration, so will enter free fall before the bucket does.

5. Oct 17, 2015

### AAAA

Interesting, I'm assuming that this is beyond the scope of my course-- cool regardless.

CoM = Center of Mass, correct?

6. Oct 18, 2015

Yes.