Consider a 320 mm × 320 mm window in an aircraft. for a temperature difference of 80°c from the inner to the outer surface of the window, calculate the heat loss through 10-mm-thick polycarbonate, soda lime glass, and aerogel windows, respectively. the thermal conductivities of the aerogel and polycarbonate are 0.014 w/m·k and 0.21 w/m·k, respectively. evaluate the thermal conductivity of the soda lime glass at 300 k. if the aircraft has 130 windows and the cost to heat the cabin air is $1/kw·h, compare the costs associated with the heat loss through the windows for an 8-hour intercontinental flight.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

If you were designing a bumper for a car, would you prefer it to exhibit elastic or plastic deformation? why? consider the functions of a bumper in both a minor "fender-bender" and a major collision.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.