Work and energy
Work happens whenever a force moves something. Whenever someone does work on another object, like moving a chair across the floor, they also transfer energy to that object. In this case, the person moving the chair gives it kinetic energy: energy of motion.
This is part of the law of conservation of energy: Energy can not be created or destroyed but can be transferred to different objects and take different forms. This concept helps explain how fuel and engines work, and why car owners need to buy gasoline or charge their vehicles.
When a driver starts up their car, the car doesn’t create kinetic energy to move; instead, the chemical or potential energy in the fuel of the car combusts in the engine to generate motion, converting potential energy into kinetic energy.