Transcript
The forms of energy.
All forms of energy can be classified as kinetic or potential.
These two are the basic states of energy.
Potential energy is stored due to an object’s position.
Kinetic energy is energy of motion.
POTENTIAL ENERGY
1. It is stored due to the objects position.
2. Bigger objects have more potential energy than smaller objects.
3. An object at a higher elevation will have more potential energy than an object at a lower elevation
KINETIC ENERGY
1. It is energy of motion.
2. It depends on the speed and mass of an object.
3. Faster objects have more kinetic energy than slower objects.
Thermal energy
It exists because objects have heat.
Heat is caused by the motion of tiny particles.
Thermal energy can changes matter:
Mechanical energy
It is the energy associated with the motion and position of an object.
It is the sum of kinetic and potential energy.
Electrical energy
It is created by the movement of electrons.
Not all objects conducts electricity, this objects are call insulators. Ex: wood.
Magnetic energy
It is the energy made by the magnetic attraction or repel of two objects, for this to happen there should be two poles: negative (N) and positive (S).
Chemical energy
Energy stored in chemical bonds that can be released. Ex: food, fossil fuels, battery acid.
The most common use of chemical energy is the food we consume to generate enough energy to live, work, think, etc.
Elastic energy
It is the energy stored in the form of a material or physical system as work is performed to distort its volume or shape and it happens when objects are compressed and stretched.
Example of a use for elastic energy include a rubber band, spring, bouncing ball, catapult, bungee cord, bow string and trampoline.
Nuclear energy
It is energy inside the nucleus of an atom. Atoms are tiny particles that make up every object in the universe.
The nuclear energy is created in a nuclear power station.
Example of a use for nuclear energy: human health, sterilization of food, determination of age, use in space and generating electricity.
Gravitational energy
It is due to the force of gravity caused by the attraction of all other masses to the mass of the earth.
At a higher elevation, you give the object more gravitational energy.
The most common use of gravitational potential energy is in hydroelectric power plants that use the GPE of water to generate electricity.
General classification of energy sources: renewable
and non-renewable.Advantages and
disadvantages of every group.
Advantages of renewable energy
1. Renewable energy: It is infinite.
2. Environmental Benefits: It is clean
3. Reliable Energy Source: Reduce our dependence on fossil fuels and the result is minor vulnerable to political instabilities for trade disputes and wars.
4. Economic Benefits: stables jobs, require a less amount of maintenance, which reduces the costs.
5. Stabilize Energy Prices: Non dependant of other countries.
Disadvantages of renewable energy
1. Reliability of Supply: It is dependant of the climate.
2. Difficult to Generate in Large Quantity: It cannot be sufficient for all the consumptions demand.
3. Large Capital Cost: It is careful planning and implementation.
4. Large Tracts of Land Required: It needs large extensions of land.
Advantages of non-renewable energy
1. They are easy to transport from one area to another. For example petroleum oils which can be transported via pipes.
2. Cost of producing is low since they are naturally available.
3. Most of this energy sources are abundantly available in different areas.
4. Their availability is not affected by climatic condition.
Disadvantages of non-renewable energy
1. Environmental Consequences. They have a very negative effect on the environment when mined, processed and consumed.
2. Health Risks. Cancer, allergies and other illnesses are associated to the contamination that this energies produce in the Earth.
3. Supply and Demand. Because unsustainable energy reserves are limited, they will become more and more expensive as they are used.
4. Running Out. All non-renewable energy resources will spent.
Bibliography
https://www.youtube.com/watch?v=nlpD6BT0YuM
https://www.youtube.com/watch?v=SCg81A6kwg0
https://www.youtube.com/watch?v=86PzkRbw4_U
http://en.wikipedia.org/wiki/Forms_of_energy
http://en.wikipedia.org/wiki/Chemical_energy
Non-renewable energy
we have a low production and a high consumption of the product.
But first, what does non-renewable means?
Natural gas
Water is inserted in the reservoirs for making pressure increase and gasses will go up, then water an gas are divided.
Nuclear EnergyComes from
uranium
The nuclear energy is produced during the process of fission and fusion of atoms.
In blue we have protons and in red neutrons.
As in coal energy we use thermal energy to heat up water.
The pressure in the circuit will increase and water vapor will get to a turbine.
This turbine will move transforming thermal energy into mechanical energy.
TECHNICAL SYSTEMS
Alternative energies are obtained from inexhaustiblesources. The most used ones are:
• - Hydroelectric• -Tidal Power Plants• - Thermosolar Power Plants• - Photovoltaic panels • - Wind farms• - Biomass• - Geothermal
Hydroelectric : energy is generated by releasing the water from the reservoir through the lower part of the dam at high pressure.
Tidal Power Plants : a large dike is built across an estuary in the ocean in which there are channels in the lower part of the dam, in the seawater.
Thermosolar Power Plant : the idea is to gather solar radiation by means of mirrors and concentrate it all.
RENEWABLE ENERGY SOURCES
• We can obtain energy from natural phenomena related to the Sun, such as the wind, tides and waves
• Scientists are currently experimenting with alternative energy sources.
Photovoltaic panels: this system is based on a property of silicon crystals which allow them to generate electricity when they are illunated by light.
Wind Farms : it consists of a large rotor placed on top of a tower and drives the electricity generator.
Biomass : refers to biological material from iving organisms. Its energy can be obtained through three processes:
Pyrolysis: the result is a gas called methane.
Fermentation of plants : results in bioethanol.
Fermentation of organic waste from rubbish: generates a product known as compost.
Geothermal : in some countries there are geological traps that contain very hot rocks. They inject water from the outside and convert the water into steam to turn a turbine that drives a generator.
• Thermal Power Plants Generation
I. Fossil-fuels (natural gas, coal, petroleum) burned heat
II. The heat generated evaporates water
III. Steam TºC Pressure turbine turns
IV. Water is condensed liquid
with cold water
Process starts again
Burned coal rises through this pipe Cold water
renovates from the rivers, lakes…
30% efficiency
• Hydroelectric Power PlantsGeneration - uses the movement of water (rivers, waterfalls, reservoirs…)
- located certain height potential energy high speed of water
- water pipe turbine generator (electric current) water
returns to the stream
The bigger the height of water, the more energy generated
• Nuclear Power Plants Generation - Heat is produced by nuclear fission split atom 2 smaller
nucleiFission chain reaction: neutrons released split again and produce more energy (e.g., uranium 235)
Process:
1. Nuclear fission in reactor
2. Nuclear fission heats water
3. This makes the turbine turn
4. The generator transforms the energy into electricity
5. Water vapour is condensed with cold water and the cycle starts again
I. Step-up transformers: increases the voltage (note that there is an
electricity energy loss, called Joule effect, when it is transported)
intensity energy loss solution: voltage
II. Transmission lines: cables joined by towers. Air insulator cheap
It can also be underground
• Transmission
I. Step-down transformers: decreases de voltage (a high voltage is dangerous)
II. It is distributed to factories and houses by cables and tranformers
• Distribution
• Efficiency Energy can’t be destroyed nor created transforms from the total
energy
Consume less same work
Advantages: Example:
- saves energy -saving light bulb
- saves money
- pollutes less
Part of it transforms and is no longer useful
Traditional light bulb Energy saving light bulb
• Energy Saving
Advantages: Examples:• Save money
• Pollute less
• Make non-renewable resources
last longer
• Turn off the lights & TV when not using
• Not use half-empty washing machine
• Use energy saving devices
• Environmental impact
• Generation Air emissions: nitrogen oxide, sulfur dioxide, carbon dioxide,
methane (greenhouse gases) Water resource use: hot water from power stations are
poured into rivers and lakes. Oxygen cannot dissolve well in hot water
aquatic living things cannot live Polluted water Land resource impact (erosion, loss of soil quality, etc.) Solid waste generation (the rests of burned coal) Radioactive waste generation (nuclear power plants)
• Distribution• Underground and transmission lines constructions. Bad effects
on land
• Noise pollution• High use of material to cover all the way to every house
• Use of energy
• Excessive or innecessary use of electricity more electricity
more pollution
• Need for more electrical devices more energy to make them in a factory more electricity
Bibliography
• http://spiff.rit.edu/classes/phys213/lectures/transform/transform.html
• http://www.alliantenergykids.com/EnergyBasics/AllAboutElectricity/000416
• http://www.duke-energy.com/about-energy/generating-electricity/nuclear-how.asp
• http://www.livescience.com/32137-what-is-nuclear-fission-.html
• http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/energy/heatrev6.shtml
• http://www.epa.gov/cleanenergy/energy-and-you/affect/
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