Final Exam Questions& Answers..

Why does a bimetallic strip bend with changes in temperature? {Ans: A bimetallic strip is made up of two different metals that are bound together. Since materials expand at different rates, when a bimetallic strip is heated (or cooled) the strip will bend. If it is heater and its temperature increases it bends so that the outside of the arc is made of a material that has a larger coefficient of expansion and if it is cooled the strip will bend so that the inside of the arc is made of the material that has the larger coefficient of expansion. A material with a large coefficient of expansion both expands more when heated and contracts more when cooled as compared to a material with a smaller coefficient of expansion.}Why are such materials as wood, fur, feathers, and even snow good insulators? {Ans: The have very few "loose" electrons.}When a 1-kg metal pan containing 1 kg of cold water is removed from the refrigerator and set on a table, which absorbs more heat from the room - the pan or the water? Defend your answer. {Ans: The higher specific heat of the water results in water absorbing more