Assignment:
1. A steel section of the Alaskan pipeline had a length of 65 m and a temperature of 21°C when it was installed. What is its change in length when the temperature drops to a frigid -46°C?
2. Dermatologists often remove small precancerous skin lesions by freezing them quickly with liquid nitrogen, which has a temperature of 77 K. What is this temperature on the
(a) What is this temperature on the Celsius scale?
(b) What is this temperature on the Fahrenheit scale?
3. When the temperature of a coin is raised by 76 C°, the coin's diameter increases by 1.90 10-5 m. If the original diameter is 1.8 ? 10-2 m, find the coefficient of linear expansion.
4. A wire is stretched between two posts. Another wire is stretched between two posts that are two times as far apart. The tension in the wires is the same, and they have the same mass. A transverse wave travels on the shorter wire with a speed of 300 m/s. What would be the speed of the wave on the longer wire?
5. A hunter is standing on flat ground between two vertical cliffs that are directly opposite one another. He is closer to one cliff than to the other. He fires a gun and, after a while, hears three echoes. The second echo arrives 2.5 s after the first, and the third echo arrives 0.5 s after the second. Assuming that the speed of sound is 343 m/s and that there are no reflections of sound from the ground, find the distance between the cliffs.
6. A refrigerator has a surface area of 4.9 m2. It is lined with 0.082 m thick insulation whose thermal conductivity is 0.030 J/(s•m•°C). The interior temperature is kept at 5°C, while the temperature at the outside surface is 25°C. How much heat per second is being removed from the unit?