Topic 1 - Machines in Society (Without the Math) Flashcards
- Explore engineering careers that involve machines and/or mechanisms, including mechanical, mechatronic and biomechanical engineering - Comprehend how engineers use their expertise to benefit communities - Analyse community problems involving machines as solutions, i.e. engineers without borders, human interface, disaster response and safety - Recognise and describe basic machines and their purpose, including: bicycle, car jack, crow bar - Identify four types of motion, including linear, rotary
What is a machine?
apparatus using mechanical power and having several parts, each with a definite function that perform a particular task.
Efficiency (machine)
relationship between useful work done by the machine of the load to the total work done on the machine by the effort
Mechatronic Engineering
Combines mechanical, electrical and computer science to develop autonomous systems
What mechatronic engineers do
design smart machines and systems that are aware of their environment and can process information to make decisions.
Mechatronic engineering industries
automation, robotics, control systems, technology
Mechanical Engineering
combines engineering physics and maths principles with materials science to design, analyse, manufacture, and maintain mechanical systems.
Mechanical engineering industries
motor vehicles development, aircraft and ships construction, propulsion design, power plants and robotics
Biomechanical Engineering
development of engineering machines in medicine
Biomedical engineering uses
production of artificial organs, surgical robots, advanced prosthetics, new pharmaceutical drugs, kidney dialysis
Sub-disciplines of Biomedical Engineering
Biomaterials, Medical Imaging, Bionanotechnology
Comprehend how engineers use their expertise to benefit communities
Infrastructure Development, Environmental Protection, Renewable Energy Solutions, Public Health and Safety, Disaster Resilience, Smart Cities and Technology.
Analyse community problems involving machines as solutions, i.e. engineers without borders, human interface, disaster response and safety
- Natural Disaster Rescue Missions- Engineers, in collaboration with humanitarian organizations, employ a range of machines and technologies to aid in disaster response efforts, enhancing both the speed and efficiency of rescue missions. Examples include Robotics and Drones
2.Environment Disaster response - Marine Oil Spills (Engineers design oil skimmers, containment booms, and subsea robots to clean up marine oil spills.), Flood Management: (Engineers design and deploy flood barriers, pumping stations, and automated drainage systems to prevent and mitigate flooding in vulnerable areas)
- Human Interface in Disaster Response - HMI for Search and Rescue Drones: Engineers design interfaces that allow rescue teams to control drones in real-time, with live video feeds and GPS mapping providing immediate feedback. reduces human error and speeds up decision-making, leading to more effective rescue operations.
- Disaster Simulation and Training- Engineers create virtual simulation environments that train rescue teams and local authorities to respond to disasters using machine-based solutions.Impact: By simulating disaster scenarios, teams can practice and refine their use of machines like drones, flood barriers, or robots, ensuring they are well-prepared for real emergencies.
Recognize and describe basic machines and their purpose - bicycle
- Recognise - simple machine made up of several mechanisms such as, wheels, gears, crank shaft, bearing etc.
- Describe - coverts reciprocal motion into linear motion through the wheels, and provides a mechanical advantage at the crank
- Purpose - allows for transportation
Recognize and describe basic machines and their purpose - Lever
A lever, like a see-saw, functions by balancing forces. When two equal weights sit at equal distances from the fulcrum, the see-saw simply reverses motion, not providing mechanical advantage. However, when two unequal weights are balanced by adjusting their distances from the fulcrum, the lever acts as a machine, making it easier for a lighter person to lift a heavier one. The Velocity Ratio is determined by the relative distances each person moves vertically, corresponding to their distance from the fulcrum, demonstrating the principle of leverage for achieving balance.
lever classification
These classes are described by the mnemonic FLE123, where the F fulcrum is in the middle for the 1st Class lever, the L load is in the middle for
the 2nd Class lever, and the E effort is in the middle for the 3rd Class lever. If your prefer the term resistance instead of load, then use the mnemonic
FRE123 instead.
1st Class or Order, 2nd Class or Order, 3rd Class or Order
1st Class or Order
1st Class or Order (Fulcrum in the middle): The effort is applied on one side of the fulcrum and the resistance on the other side. Mechanical advantage may be greater than, less than, or equal to 1. (Examples: See-Saw, Crowbar, Scissors, Claw-Hammer, Bike Brake Lever, Pliers.)
2nd Class or Order
2nd Class or Order (Load in the middle): The effort is applied on one side of the load and the fulcrum is located on the other side. The load arm is smaller than the effort arm, and the mechanical advantage is always greater than one. It is also called a force multiplier lever. However in an oar, the load arm is greater than the effort arm, and the mechanical advantage is less than one. (Examples: Wheelbarrow, Nutcracker, Bottle-Opener, Car Brake
Pedal.)
3rd Class or Order
3rd Class or Order (Effort in the middle): The load is on one side of the effort and the fulcrum is located on the other side. The effort arm is smaller than the load arm. Mechanical advantage is always less than 1. It is also called a speed multiplier lever. (Examples: Tweezers, Steam-Shovel, Hockey, Stick)
Recognize and describe basic machines and their purpose - Inclined planes
An inclined plane (ramp or wedge) is a simple machine that reduces the effort needed to lift a load by allowing force to be applied over a longer distance. Instead of lifting the load directly, which requires more effort, the ramp lets the user apply a smaller force over a greater distance. As the slope angle decreases, less effort is needed, but the distance traveled increases. If the ramp were vertical, no mechanical advantage would be gained, as the effort would equal the load’s weight.
Recognize and describe basic machines and their purpose - Screwdriver
A screwdriver is a simple machine designed to increase efficiency and comfort when driving screws. Its large handle provides a longer lever-arm, multiplying the force applied by the hand at the blade, making it easier to turn screws. The handle’s size also spreads force over a larger surface, reducing the risk of skin damage. Additionally, the screwdriver’s hardened-steel blade can withstand high stresses, enabling it to drive screws more effectively than using bare hands.
Recognize and describe basic machines and their purpose - Gear
Gears are toothed wheels that transmit rotary motion and power between them when meshed together. They can change the direction of motion, such as reversing or altering the angle of rotating shafts. Gears also provide a gear ratio when they have different numbers of teeth, which allows for changes in rotational speed and torque. Increasing speed reduces torque, and vice versa, while the overall power remains constant, aside from minor losses due to friction or other factors.
Rotary Motion
Motion that moves in a circle or revolves around an axis.
Oscillating Motion
Similar to rotary motion, but constantly changing direction by swinging back and forth about a point. Example: the pendulum of a clock.
Linear Motion
Linear motion simply moves in a straight line. Example: a train moving along a straight track.
Reciprocating Motion
Similar to linear motion, but constantly changing direction. Reciprocating motion slides back and forth along an axis. Example: the pistons in an
engine.
Random Motion
More difficult to define than the other types of motion due to its unpredictable output. Truly random machine motion is difficult to achieve and so it is
often emulated or approximated by simultaneously combining two or more types of motion. Random motion is used (or approximated), for example,
in random-orbit sanders.
Mechanical Advantage
A Large load force can be overcome by the application of a significantly smaller effort force. The relationship between the magnitudes of load and effort provides a means by which the usefulness of the machine can be quantified and compared. This is known as Mechanical Advantage (MA).
Velocity Ratio
Velocity Ratio will be greater than one for any machine that creates an output force larger than the effort force.
Velocity Ratio often remains constant for a simple machine because it is determined only by the arrangement of machine components, unlike
Mechanical Advantage, which takes frictional forces into account. For example, a screw may have a fine thread (and therefore a high Mechanical Advantage) allowing it to screw easily into timber. For each turn of the screw, the screw moves into the timber at a distance equal to the thread pitch - in
other words, the Velocity Ratio remains constant.
However, as it screws further into the timber, surface friction may increase to the point where the
screw can no longer be turned - in other words, the Mechanical Advantage is decreasing and may even become zero.
Gear Terminology and General Information : Pitch
The pitch of a gear is the distance between equivalent points of adjacent teeth along the pitch line, the pitch line is an approximation of where
there is assessed as being no slippage of the teeth against each other between mating gears.
Gear Terminology and General Information: Teeth
The teeth are the portion of the gear that make contact with the teeth on another gear. In order for two gears to mesh together the pitch must be
the same for all mating pairs. When the teeth of gears mesh properly they prevent slipping and can exhibit efficiencies of up to 98%.
