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NoFaceJack

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- Homework Statement
- A mass m hangs from two strings attached to the ceiling such that they make the same angle with the vertical (as shown in Figure 2.69: See Attached Image). The strings are shortened very slowly so that the mass is raised a distance Δh above its original position. Determine the work done by the tension in each string as the mass is raised.

- Relevant Equations
- Work done by gravity (Gravitational Potential Energy)

In the solving portion of the textbook, the reasoning of the author in solving this problem is that the net work done on the system is zero because the net force of the system is zero.

So my question is how was the system in equilibrium (net force=0)?

My thinking is that since it is stated in the problem that the object was raised very slowly, so the time it takes to move the object is very large, that the acceleration can be estimated as zero. And thus, we can estimate that the net force, and the net work are both zero.

Is my logic correct? or is there any other reasoning behind this?

Thank you very much in advance.

So my question is how was the system in equilibrium (net force=0)?

My thinking is that since it is stated in the problem that the object was raised very slowly, so the time it takes to move the object is very large, that the acceleration can be estimated as zero. And thus, we can estimate that the net force, and the net work are both zero.

Is my logic correct? or is there any other reasoning behind this?

Thank you very much in advance.