Concept explainers
Rub the palm of your hand on a metal surface for 30 to 45 seconds. Place the palm of your other hand on an unrubbed portion of the surface and then on the rubbed portion. The rubbed portion will feel warmer. Now repeat this process on a wooden surface. Why does the temperature difference between the rubbed and unrubbed portions of the wood surface seem larger than for the metal surface?
Explanation of Solution
Conducting materials are good in transferring of heat and electricity while non-conducting materials are poor in transferring of heat and electricity. Wood is a non-conducting material while metal is a conducting material.
The conductors and non-conductors are classified due to the difference in thermal conductivity. Conducting material has high thermal conductivity and non-conducting materials has very low thermal conductivity. So, heat is transferred quickly across the metals whereas it is not so with the wood. When the palm is placed on the rubbed portion of the wood surface due it very low thermal conductivity heat remained at the same place and so, wooden surface seems hotter than the metal surface.
Conclusion:
Heat is conducted quickly across the metal surface while it is not so with the wood. Hence, wooden surface seems hotter than the metal surface.
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Chapter 11 Solutions
COLLEGE PHYSICS BUNDLE
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