Data and calculations: (4 pts)
Copper 700 93.1 0.86 7.1 25.5 98
Aluminum 700 88.2 1.15 7.7 27.5 95
1. What is the unit of alpha, the thermal coefficient of linear expansion? (1 pt)
2. Calculate alpha for copper and aluminum and compare with the theoretical values, given that (alpha Cu Theoretical = 17 x 10^-6 and alpha Al Theoretical = 23 x 10^-6) (3 pts)
3. How did the linear expansion coefficients for copper and aluminum compare? How do you interpret this? (1.5 pts)
4. Explain how the linear expansion of metal rods can be used as a thermometer. What would be some of the problems with this method? (1.5 pt)
5. Most materials expand when heated. What can you conclude about alpha for materials that contract when heated? (1.5 pt)
6. When a mercury (Hg) thermometer is placed in hot water, the level of the mercury initially drops before it begins to rise. Why? (1.5 pts)
7. A steel bridge is 1280 m in length. What is the bridge's total expansion if the temperature changes from 0°C to 40°C, given that alpha Steel = 12.4 x 10^-6 (1.5 pts)
8. The slab concrete used in highway construction is set in place when the ambient temperature is 20°C. If its length at that time is 20.478 m, calculate the minimum gap required between concrete slabs if buckling is to be prevented. Assume the maximum temperature that will be reached is 55°C. alpha Concrete = 13 x 10^-6 (1.5 pts)
9. From your results, derive the coefficient of volume expansion for copper and aluminum. Show your calculations. (Only apply the final form that is established without mathematically deriving it) (1 pt)