00:01
Okay, so in this problem, we are given that for a normal person, the total surface area is given to be 2 meters squared, assuming that the room temperature is 18 degrees celsius, which is 281 kelvin.
00:18
The temperature of the skin is 30 degrees celsius, which is 3303 kelvin.
00:25
We need to find the amount of heat that our body radiates per second.
00:30
So that means we need to find the, you know, the radiation power of our body.
00:40
So, you know, to do this, we need to recall stefan boltzmann's law, which is power is equal to the area times epsilon, times sigma, time t skin to the fourth, minus t room to the fourth.
00:58
Where a is the area, the surface area, afton is the emissativity, which in this range of radiation is round 1, and sigma is defont's constant.
01:12
Defund's constant is 5 .67 times 10 and then give 8 watts per meter square k to the 4.
01:17
So all we need to do is the plugging numbers, right? so this is 2 times 1 times 5 ,000, 5 ,000, 5 .67 times 5 .67 times 10 to the negative 8 times 303 to the 4 minus 281 to the 4.
01:50
So if you plug in all these numbers, you will get the power being equal to 240, around 247...