What is the difference between thermoplastics and thermoset polymers? a)thermoplastics can be moulded to shape, thermoset cannot. b)thermoplastics have covalent bonds that can be broken and reformed, thermoset does not. c. thermoplastics have entangled polymerics units that can be untangled at elevated temperature, thermoset does not. d. thermoset plastics are more flexible then thermoplastics.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

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

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?