# Bucket being lowered vertically by a rope

1. Jun 4, 2013

### e-zero

1. The problem statement, all variables and given/known data

A 12.0kg bucket is lowered vertically by a rope in which there is 163N of tension at a given instant. What is the acceleration of the bucket? Is it up or down?

2. Relevant equations

Ft - mg = ma

3. The attempt at a solution

I solved for 'a' and got a = 3.78 m/s^2, but how do I figure out which direction?

2. Jun 4, 2013

### voko

With respect to the bucket, can the force of tension be upward? Downward?

3. Jun 4, 2013

upward

4. Jun 4, 2013

### voko

What is upward in terms of signs? Positive or negative?

5. Jun 4, 2013

### nothingkwt

If the bucket is being lowered carefully would you say that it is accelerating upwards?

6. Jun 4, 2013

### e-zero

I would say that if its lowering at a constant speed then there is no acceleration.

Also, I would say that, if anything, since its moving downwards it would be decelerating. Which I guess is the same as accelerating upwards??

7. Jun 4, 2013

### nothingkwt

Well you are right but there was no mentioning the fact that the bucket was being lowered at a constant speed. If that were the case then that means that mg = Ft which is not true in this case because it is not being lowered at a constant speed.

As for direction the answer to the question implies that the bucket is being pulled up and yet the question states that it is being lowered, so either I got confused or the question is misleading.

8. Jun 4, 2013

### e-zero

How could mg = Ft if it were lowered at a constant speed?? That would indicate that the bucket is at rest.

9. Jun 4, 2013

### Staff: Mentor

No, it would just mean that the net force is zero and thus the acceleration, not the speed, is zero. The speed could be anything, as long as it remained constant.

10. Jun 4, 2013

### e-zero

Damn, I missed again :/