>>10873150>What is energy?Energy is a conserved quantity in our universe. Classically, we have conservation of momentum and energy, which are consequences of the fact that everything is relative in time and space (move the whole universe by some amount in time and space and nothing will have changed, physically speaking), due to Noether's theorem. It's advanced stuff, but the upshot is that "conservation of energy" isn't a dogma, it's a theoretical consequence of our universe.
>What is kinetic energy?Applying force (over the course of some distance) on a massive object costs energy. The force accelerates the object, and the energy (called work) put into the object becomes its kinetic energy. If you look up the derivation of the formula for kinetic energy, you'll find that it is defined as the integral of a force over a distance. By using various definitions, this can be shaped into the familiar E_k = 1/2 mv^2. As for intuition, imagine a car with some velocity slowing down over a fixed distance. Velocity appears twice: a force must be applied to take away velocity, but the break distance is covered in short time (car goes fast), so extra force is needed due to the smaller time frame.
>What about other forms of energy?Other Anons are correct to point out that energy is a "currency". You can give something more energy, or take energy from it. For example, in the case of an object in a gravitational field: energy can be extracted by dropping it, and it can have energy put into it by elevating it.
>Is it just abstraction?Energy is an abstract concept, but it can be easily understood in everyday scenarios, see the example of gravity above. Early on you can trust on your intuitive understanding, and when you feel confident that "calculating the system's energy" is what you must do (energy is conserved, so knowing something at one point in time tells you something about another point in time), you can take the jump to abstraction.
