Chapters 1 & 2
CH 1
What is Mechanics?
 It is the science which deals with the physical state of
rest or motion of bodies under the action of the forces.
 It can be further divided in two main branches. Statics:
deals with the study of bodies at rest,
Dynamics: deals with the study of bodies in motion
CH 1
Fundamental Concepts and Principles
 Space: To fix the position of a point
 Time : To relate the sequence of events
 Mass : To distinguish behavior of the two bodies under the action of
an identical force.
 Force : It is an essential agency which changes or tend to change
the state of rest or uniform motion of body.
 Principles:
Newton's Three Laws of motion
Newton's Law of Gravitation
The parallelogram Law for Addition of forces
The principle of transmissibility of forces.
CH 1
System of Units
 centimeter-gram-second system( C.G.S.)
 foot-pound-second system (F.P.S.)
 metre-kilogram-second system(M.K.S.)
 International system of units(SI units)
 This is the modern version of metric system. It consists of 7
base units, 2 supplimenary units and number of derived
units. This is absolute system of units so they are
independent of the location where measurements are
CH 2
Statics and Particles
 Forces in a plane: A force represents the action of one
body on another and is generally characterized by its
point of application, its magnitude, and its direction.
 Vectors: It appears from the above that forces do not
obey the rules of addition defined in ordinary arithmetic
or algebra. Vectors are defined as mathematical
expressions possessing magnitude and direction, which
add according to the parallelogram law. Vectors are
represented by arrows
CH 2
Forces in a Plane
 Addition of Vectors
 Resultant of Several Concurrent Forces
 Resolution of a Force into Components
 Rectangular Components of a Force. Unit Vectors
 Addition of Forces by Summing x and y Components
 Equilibrium of a Particle
 Newton’s First Law of Motion
 Problems Involving the Equilibrium of a Particle.
 Free-Body Diagrams
CH 2
Forces in Space
 Rectangular Components of a Force in Space
 Force Defined by Its Magnitude and Two Points on Its
Line of Action
 Addition of Concurrent Forces in Space
 Equilibrium of a Particle in Space