potential energy is the energy stored in an object because of its position; increase of height or mass can increase the amount of potential energy.. kinetic energy is the energy an object has due to its motion. To increase kinetic energy, either increase mass or speed Moving is kinetic Potential energy is greater the more the mass and the height.
fossil fuels A fuel source created by the decay of biomass (plant & animal remains) that was buried and put under tremendous heat and pressure to form oil, natural gas or coal. Fossil fuels take millions of years to form and when they run out, they are not replenished. Fossil fuels put carbon dioxide into the atmosphere
biomass is the matter contained in all living or recently living organisms such as compost (decaying leaves and grass clippings), some garbage, and plant products. Fuels made from plants like corn are called biofuels and burn cleaner than fossil fuels. Ethanol and Biodiesel are two examples. Limitations – Even though biomass is carbon neutral (releases what it took in) when biomass like wood burns it releases CO 2 that was stored during its life and adds to the local air pollution. It takes large tracks of land to grow plants for fuel that could be used for food.
photovoltaic cells a device that transforms radiant (sun) energy directly into electrical energy by releasing electrons from silicon atoms and causing electricity to flow.. Limitations: large tracks of land are needed for solar arrays that will produce enough energy for cities. Solar energy is only efficient where there are many hours of sunlight. Solar does not work at night. Solar can be expensive. solar energy Energy created by capturing the light energy of the sun. Solar energy can be captured using photovoltaic cells to produce electrical energy or mirrors in solar thermal plants to produce heat. Two of the biggest solar thermal plants are in California and Nevada http://micro.magnet.fsu.edu/primer/java/solarcell/
hydroelectricity Electricity created by flowing water going through a dam, which in turn causes turbines to spin which generates electricity. Limitations: Can only be located where rivers flow and lose elevation. Building dams are expensive and disrupts the habitat of plants, animals and people in the area. http://techalive.mtu.edu/meec/module17/humaninfluence.htm
wind energy Energy using wind that is converted into electricity through the spinning of blades on a wind generator. Wind farms are large groups of wind turbines which require large tracks of land. Limitations: Need continuously windy areas. Can kill birds. http://techalive.mtu.edu/meec/module17/humaninfluence.htm
geothermal energy heat energy created by the Earth captured below the surface and used to change hot water to steam which then spins turbines to produce electricity. limitations: Can only be located in areas that have hot spots where magma heats rock underground. This means that these areas are also subject to earth quakes. http://techalive.mtu.edu/meec/module17/humaninfluence.htm
Nuclear Energy is non-renewable but very efficient and does not pollute the air. Nuclear energy is a source of energy that is produced through the fission (breaking apart) of uranium 235 atoms. Heat energy is released in a reactor. Heat is used to produce steam to turn a turbine. Limitations: safety issues and radioactive waste products. Know what is happening currently in Japan from movie we saw. Steam not smoke
Risk and Reward. All technology has rewards and risks for its use. For example a cell phone allows you to communicate easier, but can cause you to be distracted and puts out radiation that could be damaging over long term. To make good decisions about using technology, we must do a risk/reward analysis. Risk Reward analysis