Consider a gray and opaque surface at 0oC in an environment at 25oC. The surface has an emissivity of 0.8. If the radiation incident on the surface is 240 W/m2 , the radiosity of this surface is

By sj wilson · 2005 ·  related articlesschool violence prevention programs fell into four broad categories: universal interferes with their efforts to teach. program for children attending any grade, pre-k through 12th 

Lexy is correct because angle r is between the incident wave,  n  = 0, and a diffracted wave.

Distance covered = speed x timethe distance traveled going against the stream = distance traveled with the stream.therefore it is the speed and the time that are the variables.as he travels the same distance both ways, speed x time is the same for each way.going upstream his speed is 4 kph; going downstream his speed is 6 kph.therefore we have two simultaneous equations: time upstream x 4 = time downstream x 6time upstream + time downstream = 60 minutestherefore we have the equation: time upstream = 6/10 hour, time downstream therefore = 4/10 hour.distance traveled at 4km/hr in 6/10 hour = 24/10 = 2.4km.check: distance traveled at 6km/hr in 4/10 hour = 24/10 = 2.4km.