The length of a metal rod is measured to be 20.08 cm using a steel ruler when both the rod and the ruler are at 22oC. Both the rod and the ruler are raised to a temperature of 253oC. When the rod is measured at this higher temperature, its length is found to be 20.32 cm.(adsbygoogle = window.adsbygoogle || []).push({});

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a) What is the coefficient of expansion of the metal?

b) You now make a rod of the same material but with twice the length. What will it coefficient of expansion be?

c) You now make a rod of the same material but with twice the diameter. What will it coefficient of expansion be?

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So far I am stuck on part a. If I can get this part, then I should be able to get the rest.

Now I know that the equation is delta L=L*(coefficient of expansion)*(delta T)

Now it appears that I have all the informatin given in the problem, so I plug it into the equation, but it doesnt work. Then I realize that the ruler is stretching also, which means the number scale on the ruler also changes. Now I have to somehow relate that number scale to the coefficient of expansion, but I'm not sure how.

I know from the book at the coefficient of expansion for steel is 11*10^-6 /degree C.

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# Homework Help: Expansion of ruler and rod help

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