Physics is the study of the physical world, ranging from subatomic domains to the structure of the universe as a whole. The goal of physics is to understand how the natural world operates, and to apply that understanding to further discovery and invention. Physics is the most basic of the natural sciences, and is used by the other sciences (such as chemistry, biology, geology, astronomy, and meteorology, which all apply physics). Life sciences use physical principles as well (for example, the understanding of the circulation system requires the understanding of fluid dynamics). Many technologies are direct applications of physics. Workers in heating, ventilation, and refrigeration technologies must understand thermodynamics and the behavior of fluids. Civil engineers, who design roads, bridges, and dams, require an understanding of the equilibrium of forces. Physicists were involved in the inventions of so many of the gadgets we use every day, from the refrigerator in our kitchens to the cell phones in our pockets.
View some you-tube physics here and here.