laws of motion, energy

who came up with the laws of motion?

what does the first law say?

what is friction

a car crash represents what principle of motion?

what type of energy is released when a sky diver jumps from a plane?

what is potential enegy?

a bike going down hill, it's an example of what type of energy?

what is electrical energy?

what is elastic potential energy?

fire wood is an example of what type of energy?