Physics chapter 7 Flashcards
Renewable sources of energy
- Sun
- Water power
- Wind power
- Wave power
- Biomass fuels (Wood, Animal dung and Biogas)
- Geothermal
Non-renewable sources of energy
- Fossil fuels
i) Natural gas
ii) Petroleum
iii) Coal - Nuclear
i) Uranium
ii) Plutonium
How far away is the sun
150 million kilometers away
How long does it take the light from the sun to reach us
8 minutes
Average temperature of earch
15 degrees Celsius
How does electricity come from the sun
Using solar cells called photocells to absorb sun rays and turn them to electricity
Examples of the uses of energy from the sun
- Solar powered spacecraft
- Solar powered emergency phones in desert regions such as the Australian outback
- Most hydroelectric power comes ultimately from the sun.
Describe the water cycle
The sun’s rays cause the water to evaporate from the oceans and the land surface. They form clouds and cause rains. this is called the water cycle
Define percipitation
Water released from the clouds as rain, snow or hail. Most precipitation falls as rain.
Define evaporation
The process by which water changes from a liquid to a gas or vapor
Define condensation
It is the change in the physical state of matter from gas to liquid
How the sun is responsible for wind power
The sun heats up the atmosphere and this causes a convection current (hot air rises and cold air falls)
Define convection
The transfer of heat by the movement of a liquid or gas between areas od different tempature
How is the sun responsible for wave power
The wave is mostly due to the wind. The frictional effect of the wind on the water makes ripples that overtime increase the amount of energy it can transferred causes waves.
How does wave power work
The up and down motion of the waves must be used to turn the turbine which then turns the generator. However, rough seas are a hazardous place to work in and on calm days it produces no power.
Define biomass fuels
Biomass fuels are organic materials produce in a renewable manner.
Name the 2 categories of biomass fuels
Woody fuels and Animal wastes
Name 5 types of biomass fuels
- Wood
- Garbage
- Crops
- Landfill gas
- Alchohol fueles
Define fossil fueles
They are hydrocarbons, primarily coal, fuel oil or natural gas formed from the remains of dead plants and animals
How are coals formed
trees put under pressure and heat become coal
How are oil and gas formed
remains of shrimp-like creatures microplankton formed oil and gas
How is petroleum made
When large quantities of dead organisms, mostly zooplankton and algae, are buried underneath sedimentary rock and subjected to both intense heat and pressure over a long time.
How is nuclear energy obtained
It comes from splitting atoms in a reactor to heat water into steam, turn a turbine and generate electricity
How is geothermal energy obtained
Water is pumped into heated rocks where it is converted to steam, which then rises up to power the turbines and generate electricity. The excess water is cooled and repeated.
uses of geothermal hot water
- heating buildings
- Raising plants in greenhouses
- Drying cops
- heating water as fish farms
- Industrial processes such as pasteurizing milk
Define tidal energy
It is similar to hydroelectric power stations as the moving water enters through the turbines and exits. It is reliable and renewable
Advantages of non-renewable resources
- Produces little to no waste
- Non-renewable energy also has market value where a supplier or manufacturer makes money and pays workers enhancing economies.
- Widely available and affordable
Disadvantages of non-renewable energy
- Once gone they can not be replaced or revitalized
- Pollution grows greater through the by-products they leave behind and mining non-renewable energy is causing damage to our environment
- They contribute to global warming.
Advantages of renewable energy
- They are nearly infinite
- A very large amount of energy could be generated in this way
- A barrage could be used in various ways, as a bridge or as a barrage against flooding
Disadvantages of renewable energy
- Sunlight is only found during the daytime which makes it inconvenient to use at night
- Wildlife could be affected
- Construction of barrage could be expensive
Energy’s originating from the sun
- Fossil fuels- Store energy from the sun
- Radiation- absorbed by solar panels to provide hot water and electricity
- Wind causes air movements to generate electricity through turbines
- Most hydroelectric power comes from the sun, water evaporates
Energy not from the sun
- Tidal power- The moon contributes to the ocean’s tide
- Nuclear power- Uranium was in the ground since the earth was formed
- Geothermal energy- Depends on the presence of radioactive substances inside the Earth
Source of the suns power
Energy released form the sun is nuclear fusion as two energetic hydrogen atoms collide and fuse to form an atom of helium
What is fission
The splitting of a heavy, unstable nucleus into two lighter muclei
What is fusion
The process where two light nuclei combine together releasing vast amounts of energy
Advantages of Nuclear fusion
- Low operating costs
- Global climate compatible
- Nuclear energy helps countries grow economically
- Nuclear energy may be used in a range of methods
- This power production is a very reliable supply of energy for us
Disadvantages of Nuclear fusion
- The initial investment is quite hefty
- People exposed to it have health issues
- With nuclear electricity, there are long-term storage expenditures to comp;let
- Uranium mining is vital to keep the nuclear energy market viable
- Constructing a new nuclear power plant can take a very long time.
Internal energy vs thermal energy
Internal energy is all the energy inside the object while thermal is the average amount of energy in an object
Define tempature
The average kinetic energy in an object
Define conduction
Heat energy transfering through solid
Define convection
Heat being transferred through gas or liquid
Define Radiation (Heat)
Heat energy transfering through vacuum or air.
