Question About Work-Energy Theorem

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Discussion Overview

The discussion revolves around the application of the Work-Energy Theorem in the context of a homework problem involving multiple forces acting on an object. Participants explore the relationship between work done by forces and the change in kinetic energy.

Discussion Character

  • Homework-related, Conceptual clarification

Main Points Raised

  • One participant questions whether it is valid to express the total work done by multiple forces as the sum of individual works, stating: ∑W = ΔK.
  • Another participant confirms that this expression is correct, stating "Yes. Precisely."
  • A later reply emphasizes that in Newton's second law, the force considered is the net force, implying that the work in the theorem refers to net work done on the object.

Areas of Agreement / Disagreement

There appears to be agreement on the application of the theorem as it relates to net work and kinetic energy, but the discussion does not explore any competing views or unresolved issues.

Contextual Notes

The discussion does not address any specific limitations or assumptions regarding the application of the theorem in different contexts or scenarios.

Who May Find This Useful

Students working on problems related to the Work-Energy Theorem and those interested in the relationship between forces and energy in physics.

dlacombe13
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Very simple question. So I am on a homework problem, and I want to make sure that I am using this theorem correctly. My book states that the Work-Kinetic Energy Theorem is:

W=ΔK

Now the solution to this problem involved multiple forces and thus each force is doing work. So my question is, is it legal to say that:

∑W = ΔK
 
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dlacombe13 said:
Very simple question. So I am on a homework problem, and I want to make sure that I am using this theorem correctly. My book states that the Work-Kinetic Energy Theorem is:

W=ΔK

Now the solution to this problem involved multiple forces and thus each force is doing work. So my question is, is it legal to say that:

∑W = ΔK

Yes. Precisely.
 
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Likes   Reactions: vanhees71 and dlacombe13
Thank you, the problem makes complete sense to me now!
 
In Newton's second law, F = ma, F is always the net force acting on an object. Therefore, in the work-energy theorem, W is always the net work done on the object.
 

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