An 80 watt filament looses all its energy by eadiation from its surface. The emissicity of surface is 0.4. the area of sciface is 5x105m². Calculate temp of filament. Neglect temperature of surroundinge- Stefen's constant (0) = 5.67 x 158 w/m³²kh.

An object emits 30 Watts of power. If it were a perfect black body, other things are being equal, it would emit 90 Watts of radiant power. What is the emissivity of the object?

What is the value of Heat Flux in KW/m2 in the Heat Flux Gauge?

The next four questions use this description.  Our Sun has a peak emission wavelength of about 500 nm and a radius of about 700,000 km. Your dark-adapted eye has a pupil diameter of about 7 mm and can detect light intensity down to about 1.5 x 10-11 W/m2.  Assume the emissivity of the Sun is equal to 1. First, given these numbers, what is the surface temperature of the Sun in Kelvin to 3 significant digits? What is the power output of the Sun in moles of watts?  (in other words, take the number of watts and divide it by Avogadro's number) Assuming that all of the Sun's power is given off as 500 nm photons*, how many photons are given off by the Sun every second? Report your answer to the nearest power of 10 (e.g. if you got 7 x 1024, give your answer as 25).