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Thermal Physics Question1. The distance between the 20oC mark and the 100oC mark on a mercury thermometer is 25.0 cm. When the mercury is 5.0 cm below the 100oC mark, what is the approximated temperature. Analysis: 2. In Singapore, we often switch on the air-conditioner to cool our rooms as the weather is very hot. However, in temperate countries where the weather is cold, the rooms need to be heated up. Figure below shows a method of heating a room using solar energy instead of conventional sources of energy. A brick wall with a blackened surface is placed behind a double-glazed window facing the Sun. During the day, the wall stores energy received from the Sun as heat energy. At night, the heat from the blackened surface is transferred to the air next to it. (a) Black surfaces are good absorbers of infra-red radiation / radiant heat, enabling more heat to be stored during the day. 3. Double boil cooking is a process by which food is cooked using indirect heat. The diagram below shows a cross-sectional view of how it is done. (a) Conduction from heat source into external flask to water in the external flask. Conduction from water (external flask) to Inner flask and water in it, then to food. 4. The graph below shows the heating curve of an unknown substance X. (a) The melting point is 120oC and the boiling point is 250oC. 5. 0.20 kg of ice at -3oC was added to 2.0 kg of water at 28 oC. What is the final temperature of the resulting cold water? Analysis: |
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