The reason we break down the system is because the Earth is much too complex to try to understand all at once. A dynamic system is a system that is constantly changing. The Earth is a complex dynamic system because it has numerous parts, that all are interconnected and working together, and these parts are constantly changing with time. Earth has an extremely interesting history and Earth has an equally exciting future. A system needs energy to run.
Energy is the ability to do work.
Work usually involves moving matter from one place to another, causing a chemical reaction to occur. All energy is eventually turned into heat energy. This force of attraction is dependent on the mass of the objects and the distance between them. Gravity is important because it causes the planets to orbit the sun and produces convection cycles inside the Earth and in its atmosphere and oceans. Solar Radiation - Produced by fusion of hydrogen into helium.