This chapter describes the laws of Classical Mechanics, which later on we will call simply Mechanics, unless differentiation is necessary. Classical Mechanics is a part of Physics and describes the behavior of bodies with forces acting upon them. Classical Mechanics is often referred to as "Newtonian Mechanics" as Newton formulated the fundamental laws of motion on which Classical Mechanics is based.
Classical Mechanics is divided into:
- statics - studies of objects at rest,
- kinematics - studies of objects in motion, without considering the forces acting upon them,
- dynamics - studies of motion under influence of force.
The laws of Classical Mechanics are true for objects which move with speed much smaller than the speed of light and their dimensions are much larger the dimensions of atoms or small molecules. You have to realize that speeds as high as 100 km/s, that is 360,000 km/h (9 times around the Earth during one hour!) are still considered as much smaller than the speed of light (approximately 300,000 km/s = 1,080,000,000 km/h). Objects of about 100 nm in diameter (= 0.0000001 m = 0.00001 cm = 0.0001 mm) are already big enough to be governed by the laws of Classical Mechanics.
Summarizing, the laws of Classical Mechanics can be applied to all objects we deal with in everyday life, as well as to planets and galaxies. Object and phenomena which do not fulfill criteria of Classical Mechanics are the subjects of studies of Relativistic Mechanics (when moving with speeds close to light speed) and Quantum Mechanics, if they are very small (diameter much smaller than 100 nm).
The following paragraphs introduce the basic concepts of Classical Mechanics. The whole website is intended as an online textbook of Physics and it should help you in studies of physics and in solving problems.