Answer:
Total pressure in atmosphere IS 4.36 atm
Explanation:
Given Data:
Depth of lake is 400 mtr
surface tension is 147 kilopascals
surface temperature 94 kelvin
Gravity = 1.35 m/s^2
specific gravity of methane(liquid) = 0.415
specific gravity of ethane(liquid) = 0.546
density of methane can be obtained as
Density of ethane can be obtained as
Total pressure in atmosphere can be obtained as
= 441.84 kPa
= 4.36 atm
Explanation:
The Stefan-Boltzmann law establishes that a black body (an ideal body that absorbs or emits all the radiation that incides on it) "emits thermal radiation with a total hemispheric emissive power proportional to the fourth power of its temperature":
(1)
Where:
is the energy radiated by a blackbody radiator per second, per unit area (in Watts). Knowing
is the Stefan-Boltzmann's constant.
is the Surface area of the body
is the effective temperature of the body (its surface absolute temperature) in Kelvin.
However, there is no ideal black body (ideal radiator) although the radiation of stars like our Sun is quite close. So, in the case of this body, we will use the Stefan-Boltzmann law for real radiator bodies:
(2)
Where is the body's emissivity
(the value we want to find)
Isolating from (2):
(3)
Solving:
(4)
Finally:
(5) This is the body's emissivity