Greentext

4452 readers

1602 users here now

This is a place to share greentexts and witness the confounding life of Anon. If you're new to the Greentext community, think of it as a sort of zoo with Anon as the main attraction.

Be warned:

Anon is often crazy.
Anon is often depressed.
Anon frequently shares thoughts that are immature, offensive, or incomprehensible.

If you find yourself getting angry (or god forbid, agreeing) with something Anon has said, you might be doing it wrong.

founded 1 year ago

MODERATORS

Early_To_Risa@sh.itjust.works

475

Anon questions physics (sh.itjust.works)

submitted 1 month ago by Early_To_Risa@sh.itjust.works to c/greentext@sh.itjust.works

55 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] chamomile@furry.engineer 4 points 1 month ago* (last edited 1 month ago)

@SorteKanin

This also explains why evaporation cools down (like when you sweat): the molecules with the highest temperature are the ones evaporating, so the average temperature decreases as those high-temperature molecules leave the system. Only the relatively colder molecules are left behind - thus it cools as a whole.

The main principle at work here is the enthalpy of vaporization. When matter changes state, there is an associated amount of energy that is absorbed or released - in the case of vaporization, energy must be absorbed. So when sweat forms on your skin and evaporates, it absorbs heat energy from your body in order to undergo that state change.

For water, the energy involved here is remarkably high, much higher than the energy stored by a few degrees difference in temperature. For example, if you wanted to boil off 1kg of water, it would take about 300 kJ to bring the temperature up to boiling from room temperature and over 2000 kJ to boil it all into steam.