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

AI Thread Summary
A body requires energy to move, but once in motion, it does not need additional energy to maintain that motion if no external forces act on it. The kinetic energy of a moving body originates from its initial velocity. According to Newton's first law, a body in motion will continue at the same speed and direction unless acted upon by external forces. Therefore, external forces are necessary to alter the body's motion or kinetic energy. Understanding these principles clarifies the relationship between motion, energy, and external forces.
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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