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METAL: AN EXCELLENT CONDUCTOR

THE PHENOMENON

Have you ever walked through your house and touched a piece of wood, then touched a metal pipe or doorknob? Why does the metal feel colder if they are both the same temperature? This phenomenon is known as Heat Conduction and is a simple property of physics. Wood is a poor conductor of heat. Metal, on the other hand, is an excellent conductor of heat and quickly draws heat away from your skin and gives you the impression that it is cooler than it actually is. This also explains how you can put your hand in a hot oven and not be burned by the air inside, but you will feel extreme pain should you touch a metal cake pan at the same temperature as air is a much poorer conductor of heat than metal.

EXAMPLES

Other Examples of Heat Conduction

Heat conduction, also known as thermal conduction, is the process where heat is transferred within a body due to the collision of neighboring particles.

Everyday Heat Conduction
Here are some examples of the process of heat conduction:

  • A cold cast iron skillet is placed onto a stovetop. When the stove is turned on, the skillet becomes very hot due to the conduction of heat from the burner to the skillet. You decide to touch the handle of the skillet after it has been on for several minutes, and now the handle is hot, too. This is because heat was conducted through the portion of the skillet in contact with the stovetop all throughout the rest of the skillet.
  • A shirt is placed on an ironing board to be ironed. Heat from the iron is conducted to the shirt, making it easy to iron out all those unsightly wrinkles and make the shirt look sharp.
  • The engine of a car is turned on, and the hood becomes warm due to the conduction of heat from the engine to the hood of the car.
  • A cube of ice is placed into the hand of a man. Over time, heat conducted from the man’s hand to the ice cube will cause the ice to melt.
  • An individual builds a fire, and then moves around the burning logs with a poker. Heat is conducted from the burning logs to the poker, making the end of the poker become red-hot if it is left in the fire too long.
  • When a young girl walks outside barefoot on a hot summer day, the heat from the asphalt is conducted to her feet, and her feet become hot. This is because heat is conducted from the asphalt to the girl.
  • A boy grabs a penny from his tabletop, and it feels very cold to the touch. After holding it for a few seconds, the heat from his hand is conducted to the metal coin.
  • The radiator is turned on to warm a house during a cold day, and the owner of the house puts his hat on top of it. The hat becomes warmer due to the radiator conducting heat to it.
  • A boy places a hot dog onto the end of an unraveled metal clothes hanger and begins to cook it over the fire. After a time, the hanger begins to feel hot due to the heat conducted from the hot fire all along the piece of wire.
  • When a piece of hot lasagna is placed onto a porcelain plate, the plate will feel warm to the touch after several minutes due to the conduction of heat from the just-cooked food to the plate on which it sits.
  • A young boy comes inside after playing on a snowy day, and huddles up to his mother to become warm. This is because heat is transferred from his mother’s body to his own through the process of conduction.

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