PH2530: Physics Week 6
Unit 6 Problem Set 1: Applying Thermal Expansion
Learning Objectives and Outcomes
Calculate the thermal expansions of solids and liquids.
Assignment Requirements
Complete the following problem. Show all of you work.
The formula for the linear expansion of a solid is given by: An iron rod (α = 11.8 x 10-6 C-1) has a length of 1000 meters (or 1 km) at 0 degrees Celsius. If the rod must expand 10 cm to bridge a gap, to what temperature must the rod be heated?
Increase in L = a*(T-To)L = 10cm = 0.1m
11.8*10^-6/oC(T-0)1000 = 0.1
0.0118T = 0.1
T = 8.47o C
Required Resources
Scientific calculator
Submission Requirements
Submit your work on a separate sheet of paper to your instructor at the end of the exercise.
Question 1 of 1:
Temperature and Heat
Complete the following problems and exercises using complete sentences and showing all work where appropriate.
1. The temperature of the Sun's interior is about 107 degrees. Does it matter whether this is degrees Celsius or kelvins? Defend your answer.
No, it DOESN't matter whether this is in degrees Celsius or kelvins, since the DIFFERENCE between these scales is ONLY ~ 273 of either measure, and that is ABSOLUTELY NEGLIGIBLE w.r.t. the magnitude of the number 10^7. However, what is more important, perhaps, is that your value of 10^7 is itself a rather loose characterization. Modern solar evolutionary models suggest rather that the Sun's T_c is ~ 1.5 x 10^7 (degrees Celsius or kelvins) instead of merely ~ 10^7. (Our understanding of solar physics is certainly such that an error of a factor of ~ 1.5 in its central temperature would be considered way out of all reasonable possibility!) Of course the numerical factor in front of 10^7 would matter even more if one were using the (non-scientific) Fahrenheit scale. Once again, however (unlike National Geographic magazine, which should hang its head in shame over some of its conversions), one would NOT say that the Sun's central
Learning Objectives and Outcomes
Calculate the thermal expansions of solids and liquids.
Assignment Requirements
Complete the following problem. Show all of you work.
The formula for the linear expansion of a solid is given by: An iron rod (α = 11.8 x 10-6 C-1) has a length of 1000 meters (or 1 km) at 0 degrees Celsius. If the rod must expand 10 cm to bridge a gap, to what temperature must the rod be heated?
Increase in L = a*(T-To)L = 10cm = 0.1m
11.8*10^-6/oC(T-0)1000 = 0.1
0.0118T = 0.1
T = 8.47o C
Required Resources
Scientific calculator
Submission Requirements
Submit your work on a separate sheet of paper to your instructor at the end of the exercise.
Question 1 of 1:
Temperature and Heat
Complete the following problems and exercises using complete sentences and showing all work where appropriate.
1. The temperature of the Sun's interior is about 107 degrees. Does it matter whether this is degrees Celsius or kelvins? Defend your answer.
No, it DOESN't matter whether this is in degrees Celsius or kelvins, since the DIFFERENCE between these scales is ONLY ~ 273 of either measure, and that is ABSOLUTELY NEGLIGIBLE w.r.t. the magnitude of the number 10^7. However, what is more important, perhaps, is that your value of 10^7 is itself a rather loose characterization. Modern solar evolutionary models suggest rather that the Sun's T_c is ~ 1.5 x 10^7 (degrees Celsius or kelvins) instead of merely ~ 10^7. (Our understanding of solar physics is certainly such that an error of a factor of ~ 1.5 in its central temperature would be considered way out of all reasonable possibility!) Of course the numerical factor in front of 10^7 would matter even more if one were using the (non-scientific) Fahrenheit scale. Once again, however (unlike National Geographic magazine, which should hang its head in shame over some of its conversions), one would NOT say that the Sun's central