Simple Machines and Energy Sources
Simple Machines
Inclined Plane
A ramp serves to raise loads with less effort. This sloping ramp requires a smaller force than lifting the load directly, although the distance traveled will be greater.
Lathe
A cylinder with a handle coupled to a power multiplier.
Wedge
A double inclined plane where the force applied perpendicular to the base is multiplied and transmitted to the wedge faces.
Connecting Rod
A bar linkage attached to a handle, transforming circular motion into alternating linear motion or vice-versa.
Engines
Internal Combustion Engine
Compression
The piston rises and compresses the air-fuel mixture.
Explosion
The compressed mixture is ignited, expanding the heated gases and pushing the piston down.
Exhaust
The piston moves down, expelling the exhaust gases from the previous combustion.
Steam Engine
Boiling water generates high-pressure steam. This steam enters the cylinder and pushes the piston. The used steam is then condensed, creating a vacuum that helps draw in more steam.
Airplane Engines
- Turbojet
- Turbofan
- Turboprop
- Ramjet
- Pulse-jet
Gear Ratio Equation: Z1W1 = Z2W2 Where: Z = Number of teeth, W = Angular velocity, WR = Driven motor speed
Energy Sources
Biomass
The accumulated energy of living beings is used to obtain energy through burning. Environmental Impacts: Increased atmospheric CO2, solid waste accumulation.
Fossil Fuels
Coal, natural gas, and petroleum are formed from solar energy and constitute the most used energy source. They are highly polluting. Environmental Impacts: Atmospheric: Acid rain, greenhouse gas emissions, particulate matter. Aquatic: Oil spills, acidification of rivers and lakes. Terrestrial: Visual pollution, damage to monuments, land spills.
Solar Energy
A clean and free energy source. Environmental Impacts: Minimal visual pollution from manufacturing and installation.
Wind Energy
Energy from moving air spins the blades of windmills, generating electricity through a system of gears. Environmental Impacts: Atmospheric: Noise pollution, bird deaths. Terrestrial: Visual pollution.
Hydropower
Energy from stored water in dams moves turbines to produce electricity. Environmental Impacts: Aquatic: Disruption of river flow, microclimate changes. Terrestrial: Flooding of fertile lands and habitats.
Photovoltaic Energy
Sunlight is directly transformed into electricity in photovoltaic panels.
Geothermal Energy
Heat from the Earth’s interior is used to heat water and generate electricity. Environmental Impacts: Atmospheric: Release of geothermal vapors. Aquatic: Water contamination with arsenic, boron, and ammonia. Terrestrial: Risk of land subsidence.
Nuclear Energy
Splitting uranium atoms releases heat, which generates steam to drive turbines and alternators. Environmental Impacts: Atmospheric: Potential for accidents. Aquatic: Thermal pollution of rivers. Terrestrial: Visual pollution, waste storage issues.
High-Voltage Power Lines
Environmental Impacts: Atmospheric: Generation of electric and magnetic fields. Terrestrial: Visual pollution.
Tidal Energy
Environmental Impacts: Aquatic: Alteration of marine life. Terrestrial: Visual and landscape impact.
Energy Concepts
Electric Power
P (Power in Watts) = V (Voltage in Volts) * I (Current in Amperes)
Wind Turbine
A vertical structure that converts wind energy into electricity.
Boiler
A container with a heat source where hot water circulates through tubes.
Photovoltaic Cell
A device that transforms light energy into electricity.
Converter
An apparatus that transforms direct current into alternating current.
Sustainable Development
Development that balances the needs of current generations without compromising the ability of future generations to meet their own needs.
Energy Source
A body capable of storing energy and providing it through transformation.
Nuclear Fusion
The reaction produced by the union of two light nuclei to form a heavier nucleus, with a large release of energy.
Heliostat
A device with a mirror that follows the sun’s movement to maximize energy capture.
Acid Rain
Rain containing dissolved toxic gases from combustion engines and power plants.
Dam
A thick wall built in a river channel to store water.
Nuclear Fission
The fragmentation of an atom’s nucleus with the release of energy.
Transformer
A component that increases/decreases voltage and decreases/increases current.
Energy Forms
Mechanical
Associated with movement.
Thermal
Related to temperature.
Chemical
Associated with chemical reactions.
Nuclear
From the radioactive decay of atoms.
Radiant
Associated with electromagnetic radiation.
Electrical
Related to moving electric charges.
Energy Units
1 kcal = 4180 J = 4.18 kJ
1 kWh = 3,600,000 J = 3600 kJ