Thermal Energy Intuition

119 points · 13 comments · view on lemmy.world

13 Comments

JockerBlack@lemmy.ml · 31 pts · 2y (9 replies)

If you don't get it:

It takes the same amount of energy to increase the temperature of water by ~70°C (room temp=30°C and boiling point = 100°C) as it takes to send that cup of water 30 000 meters into the air. (If I did the math right)

funnystuff97@lemmy.world · 10 pts · 2y (5 replies)

My math: Boiling a cup (0.24 kg) of water from 25°C to 70°C ~45kJ (0.24kg×45°C×4182J/kg°C) Raising 0.24 kg of water up a height 30,000 m ~ 71kJ (0.24kg × 9.8m/s^2 × 30,000 m)

So my math says raising the temp of a cup of water from room temp would be equivalent to raising it about 19 km high.

Edit: I'm a moron who can't read, boiling water from 25 to 100 °C takes:

0.24 kg × 75 °C × 4182 J/kg°C ~ 75kJ

JockerBlack@lemmy.ml · 13 pts · 2y (3 replies)

Water boils at 100°C

funnystuff97@lemmy.world · 7 pts · 2y (1 reply)

God I'm stupid. I misread what you wrote as raising water to 70°, not raising water by 70°, without even thinking that that's not how you make tea. Fixed my math, and the numbers now check out.

onion@feddit.de · 1 pts · 2y

Actshually, that is how you make green tea

HappycamperNZ@lemmy.world · 5 pts · 2y

They could drink green tea, which seeps at around 70.

Or that could be jasmine, its one of them.

mkwt@lemmy.world · 1 pts · 2y

In the ISA atmosphere model, the tropopause starts at an altitude of 11 km. So you might be able to say that 19 km counts as 'stratosphere'.

mild_deviation@programming.dev · 2 pts · 2y (1 reply)

Now if only we could figure out a way to actually do that without burning a bunch of fuel for the purpose of lifting fuel! Something something tyranny of rockets.

notabot@lemm.ee · 2 pts · 2y

As with so many problems, this one can be solved with a suitably large cannon. Why you'd want to fire cups of water into the stratosphere is left as an exercise for the interested reader.

nooneescapesthelaw@lemmy.ml · 1 pts · 2y

The general formula:

MCT=MGH

So height=(heat capacity of liquid*change in temp)/9.81

In our case (4184*70)/9.81 ~ 30,000 meters

Spzi@lemm.ee · 12 pts · 2y

We could be running several space habitats by now if people just weren't drinking so much tea.

baseless_discourse@mander.xyz · 7 pts · 2y

Bertrand Russell looking at his teapot

jadero@mander.xyz · 4 pts · 2y

Is there a site that does a variety of energy comparisons

JockerBlack@lemmy.ml · 1 pts · 2y
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