3A-1 Flashcards
Machine
Is defined as a device that receives energy and uses this energy to do work
Simple Machine
receives energy from a single input force and then does work by producing a single output force.
What is Effort?
Is is synonymous with force (newtons)
What is required to achieve a Mechanical Advantage?
The effort or input energy must be applied over a greater distance than the load actually moves.
Ideal Machine
A machine that has no losses to friction. Has an efficiency of 100%. Not possible in real world
Wheel
Effort part of wheel and axle system. The diameter or radius can represent the effort distance
Axle
Load carrying part of wheel and axle system. The diameter or radius can represent the loads distance
Velocity Ratio for Pulley System
When effort is applied downwards VR = Number of Pulleys
When effort is applied upwards VR = Number of Pulleys + 1
Mass Desnity
Mass Density = Mass (kg) / Volume (m^3)
Density of Fresh Water
1000 kg/m^3
Relative Density
Relative Density = Density of Substance / 1000
What is a Beam?
It is a structural member that is subjected to loads perpendicular to its longitudinal axis.
Stress
The internal resistance to an external force is called stress
Linear Strain
When a material is subjected to sufficient external force it will become deformed in some way. When tensile or compressive stresses cause deformation this is known as linear strain.
Reaction Force
A reaction force is a force that acts in the opposite direction to an action force. Friction is the reaction force resulting from surface interaction and adhesion during sliding. Reaction forces and reaction moment are usually the result of the actions of applied forces.
Space Diagram
is a signal diagram which shows a number of different vectors all originating from a single point
Coplanar Vectors
Vectors all in the same plane
Concurrent Vectors
Vectors whose lines of action meet at one point
Regular Pyramid
A pyramid in which the base is a regular polygon and all sides are equal and all angles are equal
Quadrilateral
is any plane (two-dimensional figure) that is bounded by four straight lines. Square/Rhomboid/Rhombus/Trapezium/Rectangle
Obtuse Triangle
One angle is greater then 90 degrees but less then 180
Straight Angle
Is an angle that is exactly 180 degrees
Reflex Angle
An angle greater then 180 degrees
Radian
is illustrated by an arc of equal distance of one radius of the circle.
Absolute Pressure
A pressure scale that begins at zero, which can be defined as the pressure at which a perfect vacuum exists.
Atmospheric Pressure
The pressure of the outside at a certain location on earth. Generally calculated at 101.3 Kpa but can vary depending on elevation. The higher up you go the less atmospheric pressure is present.
Perfect Vacuum Versus Partial Vacuum
Anything below atmospheric pressure (101.3 Kpa) is considered a partial vacuum. Only when absolute pressure reaches 0Kpa is a perfect vacuum reached.
Gauge Pressure
Pressure Gauges start at atmospheric pressure. So zero on their scale is equal to 101.3 Kpa. For instance, when a gauge reads 200 Kpa the absolute pressure is actually 301.3 Kpa.
Internal Energy
Is known as the sum of kinetic energy and potential energy present in all substances due to the vibration of the molecules.
Latent Heat of Fusion
The heat required to change a unit mass of a solid to a liquid
Latent Heat of Evaporation
The heat required to change a unit mass of liquid into a gas at the same temperature and pressure