Mechanics
Mechanics is an area of science concerned with the behavior of physical bodies when subjected to forces and displacements
Particles in mechanics
Particles are either stay at rest or moving with relatively less that the speed of light
Structure
Structure is a permanent system or assembly of members designed to transmit the loads safely to a means of support
Concerns in a structure
Engineers must account for its safety, serviceability while taking into consideration economic and environmental constratints
What is a particle?
Object with mass but with negligible size
What is a rigid body?
Combination of large number of particles in which all the particles remain at fixed distance from one other after applying a load
10^9
giga, G
10^6
mega, M
10^-6
micro, u
10^-9
nano, n
What is a force?
Force is an action of body on another and is characterised by:
1. point of application
2. magnitude
3. direction
Newton’s first law
If the resultant force acting on a particle is 0, the particle will remain at rest or will move with constant speed in a straight line
Newton’s second law
If the resultant force acting on a particle is not 0, the particle will have an acceleration proportional to the magnitude of force
Newton’s third law
The forces of action and reaction between bodies in contact have the same magnitude, same line of action, and opposite sense
