A 6 kg bucket of water is being pulled straight up by a string at a constant speed.?

Part A

What is the tension in the rope?

1. about 42 N

2. about 60 N

3. about 78 N

4. 0 N because the bucket has no acceleration.

Part B

At a certain point the speed of the bucket begins to change. The bucket now has an upward constant acceleration of magnitude 3 m/s^2. What is the tension in the rope now?

1. about 42 N

2. about 60 N

3. about 78 N

4. It is increasing as the speed increases.

Part C

Now assume that the bucket has a downward acceleration, with a constant acceleration of magnitude 3 m/s^2.

Now what is the tension in the rope?

1. about 42 N

2. about 60 N

3. about 78 N

4. It is decreasing as the speed increases.

The earth’s gravity is an acceleration field of 9.8 m/s^2. Most simple physics problems assume a value of 10 for simplicity. That is the acceleration for any object on earth whose velocity is not changing.

A. if the bucket is on earth experiencing earth gravity (9.8 m/s^2), the answer is 2) about 60 N (6kg x 9.8m/s^2 = about 60 N.) In space, the answer is 4) 0 N because there is no acceleration.

B. On earth, 3) about 78 N, because you add gravity (9.8 m/s^2) and acceleration (3m/s^2) to get the total acceleration when the velocity is increasing against gravity. In space, none of the answers is correct. From this I can deduce that this problem assumes earth gravity.

C. I assume this means the bucket is being lowered still on earth. The tension is now 1) about 42 N, because the the earth’s gravity (9.8m/s^2) is being offset by the accelerated lowering (3m/s^2) to give a net acceleration of 6.8m/s^2. This times the 6Kg gives approximately 42 N.

Source(s): High school physics (I have a degree in engineering from a major technical university).

A 6-kg bucket of water is being pulled straight up by a string at a constant speed.