Near 70 years ago at school I was taught that bodies at speed have kinetic energy. I learnt that if I threw a ball into the air I gave it kinetic energy, which diminished as it rose and which was totally lost at its peak to potential energy. The maths equating potential and kinetic energies worked but it didn’t make sense and it still doesn’t.
Not long ago assisting my Granddaughter with her studies I read in her text book “anything moving has energy in its kinetic energy store”. It also described a gravitational potential energy store as “anything that has mass and is in a gravitational field”. It seems that most scientists support this view. I have even seen it spoken of in a Faraday Lecture.
When bodies in space have relative motion which body has this motion energy store? When I am running do I really have more energy than when I am at rest and if I double my speed do I quadruple my motion energy?
A ball is less than 0.0001% particles in space and my hand is equally so. Both are energy stable structures that do not want to merge because there would be no energy advantage in them doing so. When I accelerate my hand upward photon energy interactions between my hand particles and the ball particles lead to particles being pushed closer together. We feel the photon pressures on our hand particles. The ball’s particles like their stable energy state and they react to the spring like photon pressures that are pushing their particles closer together by accelerating with the hand.
When the hand stops accelerating the ball quickly releases any compression energies as thermal photons . It returns to its former round shape and stable energy state and sets off upward at whatever speed had been achieved. There is no motion related kinetic energy store. The kinetic energy formula 1/2 mv2 was derived as the energy involved in accelerating or decelerating an object. As I see it changes to a body’s state of rest or of uniform motion are how particle structures avoid taking on energies that they don’t want.
That is a substantially different view to the teaching that gives a body in motion a kinetic energy store. Can anyone tell me why we still regard kinetic energy as a motion energy store?