Science Grade 9

Suggested time allotment: 5 hours Unit 4 3MODULE HEAT, WORK and ENERGY Note: All revisions are in blue ink. The red ink as answers to the tests and activities should not be printed in LM, instead they should be printed in TG. Thanks.DRAFTOverview: Have you tried to heat a pot of tap water on a hot burner of a stove? It is observed that the water temperature increases. In this situation, heat flows from hot burner to the cold water. When two objects at different temperatures are put in contact, heat spontaneously flows from an object of high temperature to the object of low temperature. The natural flow of heat is always in the direction tending to equalize the temperature. If the two objects are kept in contact long enough for their temperatures toMarch 31, 2014become equal, the two bodies are said to be in thermal equilibrium, and there is no further heat flow between them. Let us take for example, when you have a fever. You will use fever thermometer in your armpit in able to monitor your temperature. Heat is flowing from your armpit to the thermometer; when the temperature reading stops increasing, the thermometer is then in equilibrium with your armpit, and they are at the same temperature. How can we describe the internal energy of your body and the thermometer as their temperature becomes equal? How much heat a body has or a system has? Actually, everything in our earth release heat and is governed by heat. Heat is present in any system where work is applied. Heat is energy in transit. Whenever work is done on a body, energy is transformed. For every energy transformation, it is associated by heat: it could be heat gain or heat loss. After completing this module, you will be able to: 1. demonstrate that heat can be turned to work; 2. infer that doing work releases heat; 1