3 m high and 5 m wide wall consists of 16 cm × 22 cm cross-section horizontal bricks ( k = 0 7.2 W/m. K ) K separated by 3 cm thick mortar layers (k = 0.25 W/m. K) The brick wall also consists of 2 cm thick plaster (k = 0.22 W/m. K) layers on each side of brick and 3 cm thick rigid foam (k = 0.026 W/m. K) on the inner side of the wall as shown in Fig. 3.21(a). The indoor and outdoor temperatures are 55 and 25°C and convection heat transfer coefficients on inner and outer sides 10 W/m^2.W/m 2
.K and 25 W/m^2.KW/m
2
.K, respectively. Assume one dimensional heat transfer and disregard radiation, determine the rate of heat transfer through the wall.

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.

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

Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg. k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m. k