Does a Free Particle Have Potential Energy and Kinetic Energy?

[logearav]

Homework Statement

Revered members,
A free particle is one which has no forces acting on it and since there is no forces acting on it, so there is no potential energy and E is entirely kinetic.

Homework Equations

The Attempt at a Solution

My doubt is, when no forces act on a particle, it should remain at rest and possesses potential energy only and Kinetic energy should be zero. How the converse happens here?

 

[HallsofIvy]

I am not sure what it would mean to say that there is "no potential energy" since potential energy is relative- that is, given any situation, you can choose the potential energy to be whatever value you like at anyone given point. However, your statement that "when no forces act on a particle, it should remain at rest" is not quite right. That is true only if the particle was initially at rest. If it initially has speed v (and so kinetic energy (1/2)mv^2) it will continue moving with that speed and kinetic energy. You can take the potential energy to be any constant.

 

[logearav]

Thanks a lot HallsofIvy.