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Unformatted text preview: LAB # 19 Coefficient of Linear Expansion Introduction: The average linear coefficient of expansion of a substance over a specific temperature range is defined as the fractional increase in length per degree rise in temperature. Thus: ¡ = ¢ L L 1 ¢ T (1) Although most substances have positive coefficients at ordinary temperatures, they may change to negative values for certain temperature ranges. This is true for iron at high temperatures, water near freezing, and type-setting metal near its solidification point. We wish to determine the coefficient of linear expansion for some metal rods. The results can be shown as the average values over a definite temperature range. If we write: ¡ L = L T- L then equation (1) becomes: L T = L o ( 1+ ¢¡ T ) (2) Apparatus: Expansion tube apparatus and steam generator (See Fig. 1), 2" elevation block, Digital ohmmeter, rods of Steel, Cu and Al metal....
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- Fall '08
- Physics, #, Coefficient of thermal expansion, 0.01 mm, Chemistry and Physics, Rhot