Air expands adiabatically in a piston-cylinder assembly from an initial state where p1 and t1 1000 °r, to a final state where p2 60 lbf/in.2 the process is polytropic with n 1.4. the change in specific internal energy, in btu/lb, can be expressed in terms of temperature change as au (0.171) (72 - t1). determine the final temperature, in r kinetic and potential energy effects can be neglected.

Select the word from the list that best fits the definition classification of most stars on the h-r diagram

Clothing made of several thin layers of fabric with trapped air in between, often called ski clothing, is commonly used in cold climates because it is light, fashionable, and a very effective thermal insulator. so it is no surprise that such clothing has largely replaced thickand heavy old-fashioned coats. (a) consider a jacket made of five layers of 0.1-mm-thick synthetic fabric (k = 0.13 w/m·°c) with 1.5-mm-thick air space (k = 0.026 w/m·°c) between the layers. assuming the inner surface temperature of the jacket to be 28°c and the surface area to be 1.25 m2, determine the rate of heat loss through the jacket when the temperature of the outdoors is 0°c and the heat transfer coefficient at the outer surface is 25 w/m2·°c. (b) what would your response be if the jacket is made of a single layer of 0.5-mm-thick synthetic fabric? what should be the thickness of a wool fabric (k = 0.035 w/m·°c) if the person is to achieve the same level of thermal comfort wearing a thick wool coat instead of a five-layer ski jacket?

Select the correct answer. what does the process of natural selection involve?