PHYSICS is the natural science that involves the study of matter and its motion and behavior through space and time.
Modern physics began in the early 20th century with the work of Max Planck in quantum theory and Albert Einstein's theory of relativity. Both of these theories came about due to inaccuracies in classical mechanics in certain situations. Classical mechanics predicted a varying speed of light, which could not be resolved with the constant speed predicted by Maxwell's equations of electromagnetism; this discrepancy was corrected by Einstein's theory of special relativity, which replaced classical mechanics for fast-moving bodies and allowed for a constant speed of light.
MAIN CONCEPTS ABOUT PHYSICS
PHYSICS DISCOVERIES AND LAWS:
The goal of physics is to develop precise models of physical reality. The best case scenario is to develop a series of very fundamental rules to describe how these models function, rules which are frequently called "laws" after they have been used successfully for many years.
The tools that physicists use range from the physical to the abstract, from balance scales to laser beam emitters to mathematics. Understanding this wide range of tools and the methods for applying them is essential to understanding the process that physicists go through in studying the physical world.
THERMODYNAMICS AND HEAT:
Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy and Heat is energy can be converted from one form to another, or transferred from one object to another.
WAVES AND SOUND:
In physics, a wave is an oscillation accompanied by a transfer of energy that travels through a medium (space or mass) and sound is a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a transmission medium such as air or water.
LIGHT AND SPECTRUM:
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word usually refers to visible light, which is visible to the human eye and is responsible for the sense of sight and a band of colours, as seen in a rainbow, produced by separation of the components of light by their different degrees of refraction according to wavelength.
FORCE AND MOTION:
A Force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest) and Motion is a change in position of an object over time. Motion is typically described in terms of displacement, distance, velocity, acceleration, time and speed.