Why Mass of a Body is Not Considered When Calculating Work

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Discussion Overview

The discussion revolves around the concept of work in physics, specifically questioning why the mass of an object is not explicitly considered in the calculation of work, which is defined as force multiplied by displacement. The scope includes conceptual clarification and technical explanation related to the definitions and implications of work in different contexts.

Discussion Character

  • Conceptual clarification, Technical explanation, Debate/contested

Main Points Raised

  • One participant states that work is defined as force times displacement and questions the relevance of mass in this calculation.
  • Another participant asserts that mass is indeed considered since force is defined as mass times acceleration, implying that mass plays a role in the overall dynamics.
  • A different viewpoint suggests that when calculating work done by a force, the mass of the object is irrelevant, as the work done remains the same for a given force and displacement, regardless of the object's mass.
  • Another participant emphasizes the importance of keeping the definition of work simple and notes that defining work as force times displacement allows for a focus on the energy input without needing to consider the specific effects on kinetic or potential energy.

Areas of Agreement / Disagreement

Participants express differing views on the role of mass in the calculation of work. Some argue that mass is not relevant to the work done, while others contend that mass is inherently involved through its relationship with force. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Participants highlight that the definition of work can vary based on the context of energy changes involved, such as kinetic versus potential energy, which may influence how mass is perceived in relation to work.

Jefferson1986
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I found that work is Force * Displacement

When a force is applied on a body and the body is displaced

My query is why mass of the body is not considered when work is calculated?

Please answer.
 
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Mass is actually considered. Force is mass times acceleration.
 
Jefferson1986 said:
I found that work is Force * Displacement

When a force is applied on a body and the body is displaced

My query is why mass of the body is not considered when work is calculated?
To calculate the work done by a force, the mass of the object is irrelevant. If you push with the same force for the same displacement, the work you do is the same regardless of the object's mass. And if that's the only force acting, then the change in the object's kinetic energy will be the same, regardless of its mass. (The resulting speed will depend on the mass, though.)
 
Where possible, it is best to keep a definition simple - involving as few variables as possible. There are a million different ways of doing 1kJ of work, some involving a lot of change in Kinetic Energy (throwing something) and some involving more of a change in Potential Energy (raising something slowly). By defining work in terms of force times displacement in the direction of the force (- important to include that!) you eliminate the need to consider what the work is actually 'doing', because that is not necessarily relevant to the energy that is put into the process.
 

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