Confusion about the Work-Energy Theorem

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SUMMARY

The Work-Energy Theorem is expressed as W = ΔE, indicating that the work done on or by a system results in a change in the system's energy. The discussion highlights a common confusion regarding the omission of potential energy (PE) in the equation W = ΔKE, which is often presented in textbooks. This exclusion typically occurs when potential energy is either not yet introduced in the material or assumed to be constant in the context being discussed. Understanding this theorem requires a clear connection between work and energy changes, specifically kinetic energy (KE) and potential energy.

PREREQUISITES
  • Understanding of the Work-Energy Theorem
  • Familiarity with Kinetic Energy (KE) and Potential Energy (PE)
  • Basic knowledge of mathematical computations in physics
  • Conceptual grasp of energy conservation principles
NEXT STEPS
  • Study the derivation of the Work-Energy Theorem in classical mechanics
  • Explore the relationship between work, kinetic energy, and potential energy
  • Investigate scenarios where potential energy is assumed constant
  • Learn about energy conservation in closed systems
USEFUL FOR

Students of physics, educators explaining the Work-Energy Theorem, and anyone seeking clarity on the relationship between work and energy transformations in mechanical systems.

AznBoi
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Is this expression always true?: [tex]W=\Delta E[/tex] Please explain why this is using mathematical computations. I understand it conceptually but I just can't connect the two mathematically.

Also, why does my book only have the expression: [tex]W= \Delta KE[/tex] rather than: [tex]W= \Delta KE + \Delta PE[/tex] why did they leave the Potential energy out of the expression?
 
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The equation [tex]W = \Delta E[/tex]
is simply saying that work done on or by a system causes a change in energy of that system.

As for your textbook, it's hard to say why it left out the potential energy factor, but most likely it is because it has not yet discussed potential energy in that specific section or the potential energy is always assumed to be constant for that particular section.
 
Work is Delta KE

You can look at work as potential.
 

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