Question

Suppose you have a box one meter cach direction. The temperature of the box is 300K. What is the luminosity? ( Watt of the box is sooer long in cach direction. There are 6 sides to the box). A. 220 Watts B. 275 Watts C. 2750 Watts D. 22,000 Watts E. 39,500 Watts

Answer 1

C. 2750 Watts

Step-by-step explanation:

Length of the each side of the box is,

`a=1m`

Total surface area of the box,

`SA=6a^(2)\\ SA=6m^(2)`

And the temperature of the box is,

`T=300 K`

From the Stefan Boltzmann law 1 square meter will emit light is,

`\sigma T^(4)`

`\sigma` is the Stefan constant of value,
`\sigma=5.67* 10^(-8)Wm^(-1)`

Therefore luminosity is,

`L=\sigma T^(4)* SA`

Therefore

`L= 5.67* 10^(-8)Wm^(-1)* (300)^(4)* 6\\L=2755.62 Watts\\`

Therefore, the luminosity is 2755.62 watt which is quite close to 2750 Watts which is given in options.