In ambient air at tinf= 35°c for the following configurations: or the tollowing configurations: a)-calculate the total heat transfer (q) from a building with four equally-sized 30m-tall and 15m-wide vertical walls. after sunset, one of the walls is 45°c, and the other three are at 40°c. the roof is 15m by 15m, at a temperature of 50°c.

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

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false