Why do some physics textbooks say P = dK/dt and others say P = dE/dt?

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Homework Help Overview

The discussion revolves around the definitions and relationships between power (P), kinetic energy (K), and energy (E) as presented in different physics textbooks. Participants are exploring the context in which these terms are used and how they relate to each other.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are questioning whether E is assumed to equal K in certain contexts and are seeking clarification on the definitions of P, K, and E. There is also a discussion about the generic definition of power and its relation to energy transfer.

Discussion Status

The discussion is active with participants seeking clarification on terminology and definitions. Some guidance has been provided regarding the generic definition of power and its application in different scenarios, but multiple interpretations of the relationships between the terms are still being explored.

Contextual Notes

There appears to be some confusion regarding the assumptions made in different textbooks about energy types and their relationships, particularly in the context of kinetic and potential energy.

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Homework Statement
I am interested in why some physics textbooks say P = dK/dt (namely morins classical mechanics) while others say that P = dE/dt (namely physics for scientists and engineers with modern physics)
Relevant Equations
P = dK/dt = dE/dt
Are they assuming that E = K in physics for scientists and engineers with modern physics, but I though E = K + U?Many thanks!
 
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What is P, K and E?

Is P power, is K kinetic energy and E is energy, what kind of energy?
 
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malawi_glenn said:
What is P, K and E?

Is P power, is K kinetic energy and E is energy, what kind of energy?
Thanks for your reply @malawi_glenn! Here I'll send you a screen shot what it says.
 
1670133901931.png
 
The text pretty much explains it.

The generic definition of power is ANY energy transfer, like transfer of heat etc.

Then in the case of an external force that is performing work, you will get P = dW/dt
 
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malawi_glenn said:
The text pretty much explains it.

The generic definition of power is ANY energy transfer, like transfer of heat etc.

Then in the case of an external force that is performing work, you will get P = dW/dt
Ok thank you @malawi_glenn!
 

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