Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It only takes a minute to sign up.
Sign up to join this community
So according to physics laws, energy can't be created or destroyed but transformed from one form to another. But what happens when an atom flows with certain velocity and is stopped by other atom's electric attraction ?
Where does that kinetic energy go? Or let's say I throw a paper ball, and it's momentum is canceled by opposite blowing ventilator. Where did the kinetic energy go?
During winter seasons, most of us rub our hands together. Actually what happens there is that the kinetic energy of our hands is being transformed into heat energy .
( Why ?)
For this to understand, first of all understand friction force. In a nutshell , I would like to tell you that it arises from the bonding of the atoms of the surfaces in contact and due to separate these bonded atoms , you must supply them energy . This energy makes them vibrate when they separate and they start wiggling here and there and this is what you feel as hot.
But you can think of friction for simplicity this way too :
Because the friction force is opposing the motion of the surfaces in contact and this force does a negative work on the body i.e. in place of giving energy to the body, the body is releasing it's own energy and this energy is your kinetic energy which is ultimately being transformed into heat.
Same is happening with your paper ball thrown against the blowing ventilator , the energy is being continuosly released into the environment as heat (For the same reason).
If their motion was supported in place of being opposed i.e. force was not in the opposite direction of motion then the kinetic energy would have increased but not transformed.
When talking about atoms , suppose two atoms approach each other and get bonded . What actually happened there is that their kinetic energy get transformed in the form of photons (this is the reason why you see flash of light during some chemical reactions) or other forms . These released energy is then absorbed by the surrounding atoms and the same process goes on. If their is nothing left for absorbing that photon , then it will be just floating somewhere in the space :)
Hope it helps ☺️.
When two atoms of gas collide at reasonable speeds (like they have in our atmosphere, for example), they bounce off one another elastically like rubber balls and no energy is lost. The direction of their momentum vectors gets changed, however.
If one atom is traveling slower than the other when they collide, the slower one picks up some momentum and kinetic energy from the faster one.
If we treat the system of two atoms, we find that momentum and kinetic energy of the two-atom system stay the same during the collision process.
