Air pressure dependent water evaporation

AI Thread Summary
Evaporation speed of water is primarily influenced by the partial pressure of water vapor above it, rather than the total air pressure surrounding it. When air pressure is lower than the water's vapor pressure, boiling occurs, which significantly increases evaporation speed. The discussion references the "Poynting correction" as a relevant concept for understanding these dynamics. There is a query about whether any liquid exhibits evaporation speed changes based on air pressure, but the consensus is that it generally does not. For further reading, exploring the Poynting correction may provide additional insights.
lesy1
Messages
12
Reaction score
0
Imagine a water basin, surrounded by air. How does evaporation speed of water change if the air pressure of surrounding air is 1.000Pa, 10.000Pa, 100.000Pa, 1.000.000Pa, 10.000.000Pa. What is an order of magnite of the evaporation speed change. Where can I read more about that?
Regards.
 
Physics news on Phys.org
The surprising answer is that it doesn't change. The evaporation speed is dependent on the partial pressure of the water vapor above it, not the total pressure of the air.

The exception to this is if the air pressure is lower than the water's vapor pressure. Then the water will boil, which significantly increases its evaporation speed (I don't know an exact number though).
 
Does there exist any liquid which would change the evaporation speed as a function of air pressure?
 
cjl said:
The surprising and incorrect answer is that it doesn't change. (snip)

You are looking for the "Poynting correction."
 

Thread 'Average velocity as a weighted mean'

Hello everyone, Consider the problem in which a car is told to travel at 30 km/h for L kilometers and then at 60 km/h for another L kilometers. Next, you are asked to determine the average speed. My question is: although we know that the average speed in this case is the harmonic mean of the two speeds, is it also possible to state that the average speed over this 2L-kilometer stretch can be obtained as a weighted average of the two speeds? Best regards, DaTario
View full post »

Thread '1:1 versus 2:1 Mechanical Advantage debate'

The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
View full post »

Thread 'Newton's first law?'

Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
View full post »

Similar threads

I Air pressure question for two different water columns
Replies
2
Views
908
B Water doesn’t fall in inverted half cup
Replies
1
Views
2K
B Cooling effect of evaporation occurs even if the surroundings are colder?
Replies
10
Views
2K
At what wind speed will salt water "boil"?
Replies
4
Views
9K
Water evaporation by negative pressure and 0% of RH
Replies
4
Views
2K
Water pressure affects air pressure
Replies
9
Views
3K
B Pressure of air inside a glass
Replies
3
Views
2K
Water evaporation in semi-open system
Replies
9
Views
3K
Understanding Pressure Changes: Air and Water in Containers
Replies
10
Views
2K
Need help trying to mimic a phenomenon associated with air pressure
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top