Secrets of Heat and Cold

Secrets of Heat and Cold — page 1
Why Are Heat and Cold Important We need heat for so many things in our lives Do you start the day with a warm shower The shower water has to be heated If you have toast for breakfast you need heat to make it If you travel to school by car or bus the engine needs heat to work These examples are just the beginning of the story Most electricity is made in power plants that run on heat 쑼 In a blast furnace iron ore is heated until the iron is molten It can then be separated from the solid slag waste Using Heat Metals must be heated to get them out of the rocks where they are found Plastics are made from oil a process that uses lots of heat Even this book needed heat to make it The paper is made from wood that was cooked in water and chemicals 4