There are lots of different types energy:
Kinetic, gravitational, chemical, heat and many more.
It is one of the the fundamental principles of physics that energy is conserved. When any energy transfer takes place, the energy we start with is transformed into some other form of energy. The energy never goes nowhere. If some of the energy appears to be wasted, then that energy has been sed to overcome forces like air resistance or friction. If this happens some energy has become internal energy of some substance, but it has not gone “nowhere”.
For each form of energy there are equations to tell us how much energy there is. If a body of mass m is moving with velocity v then it has kinetic energy and the amount of kinetic energy is given by
If a body of mass m is at a height h above the floor then it has gravitational potential energy and the amount of gravitational potential energy is given by
In the diagram below, as the skateboarder moves from position 1 to 2, his kinetic energy changes into potential energy. At 3, all the kinetic energy the skateboarder had initially has been changed into kinetic energy. The situation below has been idealised. In fact there is friction which must be overcome, and the skateboarder's potential energy at 3 will be less than that show. In practice this will mean he will not rise to a height of 3.27m.
