Science 7 Unit C: Heat and Temperature. Topic 7. Sources of Thermal Energy. pp WORKBOOK. Name:

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1 Science 7 Unit C: Heat and Temperature Topic 7 Sources of Thermal Energy pp WORKBOOK Name:

2 Read p. 238 TASK: Complete the Find Out Activity on p. 238 Energy Inputs for Energy Outputs Please record your answers below or on an attached sheet of loose leaf. Read pp Chemical Energy form of potential energy (stored) released in the form of thermal energy when wood or coal are burned Electrical Energy form of kinetic energy (moves) produced by turbines that spin using hydro-electric dams, windmills, or thermo-electric generating stations (nuclear power, HDR, or burning fossil fuels) See Figure 3.30 p. 240 Mechanical Forces forces that push or pull objects often release thermal energy friction created usually results in waste heat Example: car brakes, skidding tires, etc. Read Did You Know p

3 energy harnessed from Earth s interior Example: hot springs, geysers, etc. energy from the Sun uses the materials in the structure to absorb, store, and release solar energy. Example: south facing windows uses mechanical devices, like fans, to distribute stored thermal energy. See Figure 3.32 p. 243 o complex mechanical systems and devices used in active solar heating contain water or air that is heated and pumped through the building energy of moving air result of solar energy creating convection currents Read Off the Wall p. 244 Read p. 245 Fossil Fuels anything that can provide energy in a useful form fossil fuels are the main energy source in Alberta and around the world Example: natural gas and petroleum oils Problems with Fossil Fuels: 1) non-renewable resource at our present rate of use, fossil fuels will soon be used up See Figure 3.37 p ) pollution from burning greenhouse gases in the atmosphere, like CO 2, prevent heat from escaping into space, therefore increasing the Earth s temperature 2

4 Solar Homes BLM 3-32 Goal: Reinforce your understanding of the energy transfer systems in solar homes. Introduction Most solar homes are built with a solar collector mounted on the roof. The solar collector consists of water filled pipes beneath a layer of energy-absorbing material. The water is heated by the collected solar energy. It travels down through the pipes to a large, insulated water tank in the basement of the home. The heat is distributed from this tank to the rest of the home by a distribution system of air ducts and heat vents. What to Do Study the diagram below of a typical solar home and answer the following questions. 3

5 1. What is the purpose of the ridges on the roof? Solar Homes BLM 3-32 Continued 2. What type of material should be used to construct the ridges? 3. What role do the pipes play in the operation of the solar home? 4. Describe how the collected heat is stored and distributed to the interior of the home. 5. Explain how a pump could be used to control the amount of heat distributed throughout the home. 4

6 Read p. 247 accidental warming of the environment that results from human activities (vehicles, furnaces, generating stations, etc.) method of energy conservation where waste heat or energy from one industry is used by another industry Read Did You Know p. 247 Complete Topic 7 Review Questions p. 247 #1-5 Please record your answers below or on an attached sheet of loose leaf. 5