Physics is one of the types of science. Science works according to scientific method . The scientific method accepts only logic, reason, and experimental evidence to tell between what is scientifically correct and what is not correct. Scientists do not simply believe - they test, and keep on testing until they get satisfied. Just because some "big or well known scientist" says something is right, that thing does not become the fact of science. Unless a discovery is repetitively established in different laboratories at different times by the different people, or the same theoretical result is obtained by the clear use of established rules, we do not accept it as a scientific discovery. The real strength of the science lies in the fact that it continually keeps on challenging itself.
2. It is consideration that the laws of physics do not change from place to place. This is why experiments carried out in different nations by different scientists - of any religion or race - have always led to the similar results if the experiments have been performed honestly and correctly. We also think that the laws of the physics today are the same as they were in the past time. Evidence, contained in the light which left distant stars billions of years ago, strongly signifies that the laws operating at that time were no different than those today. The spectra of the different elements then and now are impossible to tell apart, even though physicists have glanced very carefully.
3. This course will cover the underwritten broad categories:
a) Classical Mechanics , which deals with the motion of bodies under the action of forces. This is generally called Newtonian mechanics as well.
b) Electromagnetism , whose objective is to study how charges behave under the influence of electric and magnetic fields as well as understand how charges can create these fields.
c) Thermal Physics , in which one studies the nature of heat and the changes that the addition of heat brings about in matter.
d) Quantum Mechanics , which primarily deals with the physics of small objects such as atoms, nuclei, quarks, etc. Though, the Quantum Mechanics will be treated only briefly for shortage of time.
Each and every physical quantity can be expressed in the terms of three basic fundamental dimensions: Length (L), Mass (M), and Time (T). Some examples are given below:
Speed L T -1
Acceleration L T -2
Force M L T -2
Energy M L 2T -2
Pressure M L -1T -2
You cannot add quantities that have different dimensions. So force can be added to force, but force can never be added to energy, etc. A formula is definitely wrong if the dimensions on the left and right sides of the equal sign are different.