Basic mechanical principles

Introduction to Basic Mechanical Principles

  • Understanding forces:
    • Different types of forces include gravity, friction, tension and compression.
    • Forces have direction and magnitude.
    • Newton’s Laws of Motion explain how forces affect motion.
  • Kinematics:
    • Describes the motion of objects without considering the forces that cause the motion.
    • It involves concepts like speed, velocity, and acceleration.
    • Distance-time graphs and speed-time graphs are handy tools in kinematics.

Simple Mechanics: Machines and Levers

  • Levers:
    • Understand the provenance and classifications of levers (first, second, third kind).
    • Know how levers can alter the force, direction, and distance of a movement.
  • Mechanical advantage:
    • Calculated as output force divided by input force.
    • Levers, pulleys and gears can increase mechanical advantage.
  • Gears:
    • Acknowledge how gears transfer and modify rotary motion.
    • Understand the relationship between gear size, speed and torque.

Energy and Work

  • Energy conversions and transformations:
    • Different forms of energy include kinetic, potential, thermal, electrical, and nuclear.
    • Know that energy is always conserved, but it can be converted from one form to another.
  • Work done:
    • Calculated as force multiplied by distance.
    • Work done on an object is equivalent to energy transferred to that object.

Stress and Strain

  • Tension and compression:
    • Tension concerns forces that cause an object to lengthen.
    • Compression involves forces that result in an object shortening.
  • Stress and strain definitions:
    • Stress is the internal force per unit area within materials.
    • Strain is defined as deformation resulting from stress.
  • Hooke’s Law:
    • Defines the relationship between stress and strain for solid materials under a tensile load.
    • Understand the limit of proportionality, elastic limit, and rupture point of materials.

Overview of Fluid Mechanics

  • Fluid dynamics:
    • Explains how fluids (liquids and gases) move.
    • Learn about flow rate and the equation of continuity.
    • Bernoulli’s equation explains the trade-off between pressure, height and velocity in a flowing fluid.
  • Hydraulic and pneumatic systems:
    • Understand operating principles, the use of compressible and incompressible fluids, respectively.
    • Hydraulic systems are used to transmit force in large-scale machinery.
    • Pneumatic systems are often used in tools and transport due to their cleanliness and performance.