Understanding Work


I don’t have one specific homework question, but a question about the concept of work. My book says that work is equal to the change in kinetic energy. But it also says work is equal to force x distance. So shouldn’t work be equal to the change in all mechanical energy?

For example, if a crane is lifting a beam straight up, at a constant rate, it is moving the beam a distance, by using a force, so work is being done. But there is no change in velocity (once it starts moving), so there is no change in kinetic energy, just potential energy, so according to the work-energy theorem as my book states it, no work is being done.

Can anyone help me make sense of this?

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

2. Relevant equations

3. The attempt at a solution


Leave a Reply

Name *
Email *