Acooper object that can be modeled as cube with 10 cm edges is soaking at uniform temperature of 260 c. it was suddenly placed in an environment maintained at 35 c and having heat transfer coefficient h=20 w/m2. c. the properties of the copper are as follows: rho = 8900 kg/m^3, cp=0.38 kj/kg. °c, and k=370 w/m-c. a)- calculate the time required for the center temperature to reach 90°c. b)-calculate the total heat transfer over the time period required for the center temperature to become 90°c.

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