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

[Cromptu]

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..

 

[Doc Al]

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.

 

[Cromptu]

So,the kinetic energy comes from it's initial velocity..?

 

[Doc Al]

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.

 

[Cromptu]

Thankyou :)