# A bucket of mass 1.60 kg is whirled in a vertical circle of radius 1.00 m.

1. Oct 20, 2007

### fineztpaki

1. The problem statement, all variables and given/known data
A bucket of mass 1.60 kg is whirled in a vertical circle of radius 1.00 m. At the lowest point of its motion the tension in the rope supporting the bucket is 25.0 N.
(a) Find the speed of the bucket.
(b) How fast must the bucket move at the top of the circle so that the rope does not go slack?

3. The attempt at a solution
I figured out A, the speed of the bucket to be 2.42 m/s but i dont understand how to find B.. can someone help please?

2. Oct 20, 2007

### Staff: Mentor

When the rope just goes slack what happens to its tension?

3. Oct 20, 2007

### fineztpaki

the tension decreases?

4. Oct 20, 2007

### Staff: Mentor

To what value?

5. Oct 20, 2007

### fineztpaki

less than 25?

6. Oct 20, 2007

### fineztpaki

Is there any formula i would be able to use to solve this?

7. Oct 20, 2007

### Staff: Mentor

If there's any tension in the rope, it's not slack. The only formula you need is Newton's 2nd law.

8. Oct 20, 2007

### fineztpaki

How do I get speed, or velocity (m/s) from that?
The answer is supposed to be in m/s ... i'm still confused

9. Oct 20, 2007

### Staff: Mentor

You solve part (b) the same basic way you solved part (a). What forces act on the bucket? Apply Newton's 2nd law. The differences: The bucket is at the top instead of the bottom. (What does that change?) And the tension is different. (What must it be just as the rope goes slack?)

Once you set up your equation you solve for v just like you did in part (a).

10. Oct 20, 2007

### fineztpaki

3.13

11. Oct 20, 2007

### fineztpaki

alright got it! thanks!

12. Oct 20, 2007

Yep. In m/s.