Answers: 3
Physics, 22.06.2019 06:00
Using a pedometer, you walk 3000 steps in 20 minutes, so your speed is 150 steps/min. each of your steps is 0.7 m long. what is your speed? 150 steps/min=/s=/h
Answers: 1
Physics, 22.06.2019 21:40
Engines for propeller-driven aircraft are limited in their maximum rotational speed by the fact that the tip speed of the propeller must not approach the speed of sound in air (mach i). taking 6 ft as a typical diameter for a propeller of a light airplane and 1100 fils as the speed of sound, find the upper limit on the rpm (revolutions per minute) of the propeller shaft.
Answers: 3
Physics, 22.06.2019 22:30
Materials will have different energies associated with the electrons inside them. this is related to how strongly bound they are by their work function. if we sandwich a material with a very low energy between two materials with a high energy, we create a trap for an electron. if this trap is very narrow in one direction in comparison to the others, this is approximately a 1-dimensional box that confines the electron. what is the lowest energy of an electron in the box if the thinnest direction across the materials is 4.81 nm?
Answers: 3
Physics, 23.06.2019 08:00
Athin electrical heater is inserted between a long circular rod and a concentric tube with inner and outer radii of 20 and 40 mm. the rod (a) has a thermal conductivity of ka = 0.15 w/(m*k), while the tube (b) has a thermal conductivity of kb = 0.8 w/(m*k) and its outer surface is subjected to convection with a fluid of temperature t= -15°c and heat transfer coefficient 60 w/(m2 *k). the thermal contact resistance between the cylinder surfaces and the heater is negligible. (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 15°c. (b) what is the temperature at the center of cylinder a?
Answers: 2
Is a volume of space that is empty of matter....
English, 22.07.2019 04:00
English, 22.07.2019 04:00
Social Studies, 22.07.2019 04:00
Mathematics, 22.07.2019 04:00
Mathematics, 22.07.2019 04:00
Mathematics, 22.07.2019 04:00
Computers and Technology, 22.07.2019 04:00
Mathematics, 22.07.2019 04:00
Mathematics, 22.07.2019 04:00
Mathematics, 22.07.2019 04:00
Geography, 22.07.2019 04:00
World Languages, 22.07.2019 04:00