QUESTIONS # 1-5 TOPIC 7 –PG. 247

Q. # 1. Two ways of producing electricity: Hydro-electric dams Hydro generating stations Dams use natural gravitational energy of water and are often a means of stimulating the tourist industry. But they disrupt the environment for many km’s up and down the river where they are constructed. Advantage of hydro generating stations is that they can be constructed wherever hydro is required. They burn fossil fuels ( usually coal), so they contribute to global warming and to the diminishing of our fossil fuel resources.

Q. # 2 & 3 2.Examples of converting mechanical to thermal energy are car brakes, bicycle brakes, skidding tires, shoes, and compression (when pumping up a tire). 3. Active solar energy is a way of using the Sun’s energy to heat a building. It uses solar panels and mechanical systems such as fans to store and circulate thermal energy from the Sun.

Passive solar energy uses the structure of a building to take advantage of the Sun’s radiant energy. Example, such a building will have a large, well- insulated windows facing south, and smaller and fewer windows on the other sides of the building. It will be made of materials that absorb thermal energy, and will contain draperies and furnishings that also absorb thermal energy.

Q. # 4 The greenhouse effect is a buildup of gases released by the combustion of fossil fuels. It is a problem because it prevents the thermal energy that builds up near the Earth from radiating out into space. Result: Earth’s atmosphere appears to be warming at an increasing rate. This will lead to a change in the growing conditions on the Earth and to increased flooding as the polar ice caps melt.

Q. # 5 Any energy source must be considered not just in terms of its apparent low cost but also in terms of how much thermal energy it could supply and what is involved in taking it from where it occurs to where it is needed. Up to now, developing geothermal energy resources has not seemed cost-effective or energy efficient in Alberta.