Where Does the Energy Come From for Motion Without External Forces?

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Discussion Overview

The discussion revolves around the concept of motion and energy, specifically addressing where the energy for a body's motion originates when no external forces are applied. Participants explore the implications of Newton's first law of motion and the nature of kinetic energy.

Discussion Character

  • Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants assert that a body has a natural tendency to move and requires energy to do so, questioning the source of this energy when no external forces are present.
  • Others clarify that while a body in motion does not need additional energy to continue moving, it possesses kinetic energy derived from its initial velocity.
  • One participant emphasizes that according to Newton's first law, a body will maintain its motion at the same speed and direction in the absence of external forces, indicating that external forces are necessary to alter motion or kinetic energy.

Areas of Agreement / Disagreement

Participants generally agree on the principles of motion and kinetic energy but express uncertainty regarding the source of energy when no external forces are acting. The discussion remains unresolved regarding the conceptual implications of these ideas.

Contextual Notes

Limitations include the lack of clarity on the definitions of energy and motion, as well as the assumptions regarding initial conditions and external influences.

Cromptu
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Forgive me if I'm missing a basic concept,

A body does have a natural tendency to move, but a body does need energy to move! Where does this energy come from when no external force is applied on it?

Please help, I've been pondering over this doubt since a week..
 
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Cromptu said:
A body does have a natural tendency to move, but a body does need energy to move!
It does not need additional energy to continue moving, but a moving body certainly has kinetic energy.
Where does this energy come from when no external force is applied on it?
If no external forces act on a body, it will continue its motion without the need for additional energy.
 
So,the kinetic energy comes from it's initial velocity..?
 
Cromptu said:
So,the kinetic energy comes from it's initial velocity..?
Sure.

Newton's first law just says that if there are no external forces acting, then the body continues its motion at the same speed (and thus kinetic energy) in the same direction.

External forces would be required to change the motion or the kinetic energy.
 
Thankyou :)
 

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