For this problem why would all the heat generated by the heater be absorbed by the air and not by both the inner tube and the
a very thin electrical heater is fitted between a long circular rod and a concentric tube with inner and outer radii of 20 and 40 mm, respectively. the rod (a) has a thermal conductivity of ka = 0.15 w/m⋅k. the tube (b) has a thermal conductivity of kb = 1.5 w/m⋅k and its surface is subjected to convection with a fluid of temperature t∞ = -15°c and heat transfer coefficient 50 w/m2⋅k. there is negligible thermal contact resistance between the cylinder surfaces and the heater. (a) determine the electrical power per unit length of the cylinders (w/m) that is required to maintain the outer surface of cylinder b at 5°c, and (b) what is the temperature at the center of cylinder a?

Litmus paper is made from water-soluble dyes which are extracted from lichens. this paper is used as an acid-base indicator. which of these common household substances would turn blue litmus paper red? a) bleach b) lye c) soap d) vinegar

Dying the folding patterns of protein molecules can microbiologists better understand cellular processes as well as some diseases, such as alzheimer’s, that are caused by proteins that have misfolded. the folding of these complicated molecules can be simulated on computers, but it takes a lot of processor power and time for even expensive supercomputers to do this. a group of researchers at stanford university developed software that can be used to distribute the processing of data to anyone who is willing to donate time on their idle personal computers. as a result, the researchers have been able to achieve protein-folding simulations that are far better than those other computing methods have done. which statement best describes the work of these researchers? the work is not scientific because the data are not processed in one location. the work is not scientific because the simulations are not reproducible. the researchers applied creativity to solve a problem in running an experiment. the researchers used only well-established scientific techniques.

The drawing represents the movement of particles in a substance. what changes of state can this substance undergo