Unit of work in mechanics and thermo dynamics

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Homework Help Overview

The discussion revolves around the concept of work in mechanics and thermodynamics, specifically focusing on the units of work and heat, both expressed in joules. Participants explore the implications of these units being the same across different contexts.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants question why the unit of work is the same in both dynamics and thermodynamics, with some exploring the historical context of work and its relationship to energy. Others inquire about the measurement of work when one object acts on another.

Discussion Status

The discussion is active, with various perspectives being shared. Some participants provide insights into the conceptual differences between work and energy, while others challenge these interpretations. There is no explicit consensus, but the dialogue is productive in examining the definitions and implications of work in different fields.

Contextual Notes

Participants are navigating the historical and conceptual frameworks surrounding the definitions of work and energy, indicating a need for clarity on these foundational concepts.

chandran
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unit of work and unit of heat

When we study dynamics,the unit of work is in joules which is the energy transferred to a mass which in turn is the product of force and the distance along which the force is applied

When we study thermodynamics, the unit of work is again in joules.

How these two can be same?
 
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Better, you say why should they be differant. What happens when an object does a work on an object? How do we measure work there?
 
Work is a kind of energy. I think that the reason to call it work is historically in the context of vapor machines. We use energy to move something that can replace men's labour such as moving a piston or something else.

The first law of thermodynamics says that the balance of energy is the rest (or the sum, depending on sign chriteria) of heat and work. It must have the same units so, but conceptually are different things. Work is a force times a displacement, energy that we use to move something. Heat is energy that we use to change the temperature of a system (for example).
 
Work is not a kind of energy. Rather it's a way of transfering energy.
 

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