FUNDAMENTALS
What is Mechanics?
Mechanics is the study motion and motion needs energy. For the purposes this module it can be taken to mean the interaction between forces and bodies. It allows answers to be given to questions like:
· what set of forces can be applied to a body without causing it to break
· how does an object move when a different set of forces is applied
· How does motion change with time
· What happens when bodies collide, an example of impact
All engineers require a basic understanding of mechanics, whatever their precise discipline. That is why it forms part of the core material.
· MECHANICS – the study of motion
- Motion can be either translation or deflection
· Motion needs Energy
· Mechanics
- the study of Energy
- the study of how energy is converted from one form to another
· POTENTIAL ENERGY
- The ability (potential) to do work
· Many forms
- Mechanical
§ Gravitational Potential Energy =PE
§ Motion (kinetic energy) = KE
- Electrical
- Chemical
· WHERE DOES IT COME FROM?
- The sun
THE UNIVERSAL LAW OF MOTION
& POSITION
“PRINCIPLE OF LEAST ACTION”
“When a change occurs in nature, the quantity of action necessary for the change is the least possible”
(M. de Maupertuis Lyon 1756)
“People were using the Principle of Least Action before they knew what it was”
(Wittgenstein: Tractus Philosophicus Logicus)
Why Light travels in straight lines, Laws of reflection and Refraction, Quantum Mechanics, Newton’s Laws, Laws of everything!!
CONSERVATION OF ENERGY
· ENERGY IS CONSERVED
- it can neither be created or destroyed
- it can only be transformed from one form to another
Where
UT = Total Potential Energy
Um = Mechanical Potential
Energy
Uc = Chemical Potential
Energy
Ue = Electrical Potential
Energy
Etc……
Entropy
En – energy
Tropy – Trope (form)
Entropy – energy of change
of form
