"RADIATION, POWER EMITTED vs ABSORBED, STEFAN'S LAW, BLACKBODY. The rate POWER at which energy is emitted as electromagnetic radiation by an object with surface area AREA[M] is given by STEFAN's LAW. σ is the Stefan-Boltzman constant and EPSILON is the emissivity or absorptivity. EPSILON =1 for a perfect blackbody and =0 for a perfect reflector. The same object will absorb radiation from another source and the rate of absorption is also determined by Stefan's Law. In the current situation the radiator will absorb power both from its surroundings POW_A_[W] and from another source such as steam or electricity POWER_NET[W]. Temp in °C of surroundings is TSURR[C] and that of radiator is TRADI[C]. POWER_NET[W] is the actual 'radiator' contibution. (c) Copyright PCSCC, Inc., 1993*** Answer(s) to problem *** Independent variables are set to proper values at entry. Note units in [ ]. POWER_NET[W] is supplied by source Type any key to exit. ||A household-type 'radiator' has an emissivity of 0.6 an area of2.0 m^2 (a) At what rate is radiation absorbed by the radiator when the walls ofthe room are at 27°C? (b) At what rate is radiation emitted from the radiator when its temperature is 50°C? (c) What is the net radiation rate from radiator? Type comma key to see answer. Type (F2) to return to application file."
