Verified answer

The Stefan-Boltzmann blackbody law relates intensity to temperature.

E = emissivity = 1

Stefan constant σ = 5.67040E-8 w/m^2-K^4

I = σET^4 = 698.51054 w/m^2

P = I*area = 698.51054*6*0.017^2 = 1.2112172 w

E(bulb) = 360000 J

t = E(bulb)/P = 297221.65 s = 3.4400654 days

The amount of energy the bulb radiates

= Power * Time

= 100 * 3600(sec)

= 360000 Joules.

Now we apply Stefan's law for this perfect blackbody cube.

It has six surfaces each of equal area = 0.017^2 = 0.000289 m^2.

E = 6 * (sigma) * T^4

Sigma is the emissivity of the object. For a perfect black body, it is 1.

So E = 6 * T^4 (6 because there are 6 areas which radiate energy)

Convert 60 degrees to Kelvin => 273 + 60 = 333 K (as Kelvin is the SI unit of temperature)

E = 6 * (333)^4 = 73778221926 Joules of energy/per area/per second..pretty big huh?

Now total energy = 73778221926 * 0.0000289 * 36000 = 76758862091.8 Joules

Time taken in seconds = 76758862091.8/36000 = 2132190.6 seconds = 35536.5 hours = 1480 days approx

Perfect Black Body

Its arguable and there are actually several answers to the question...