All Questions
63
questions
1
vote
1
answer
35
views
Can siphons improve the efficiency of hydroelectric dams?
Suppose we have built a hydroelectric dam where the water inlet is 100m above the outlet. We can now use the gravitational potential of the water to spin a turbine. However, suppose we install a ...
- 162
0
votes
0
answers
26
views
Energy Benefits of Using Windows Vacuums to Remove Water That Otherwise Evaporates and Absorbs Energy
I've been using a new window vac and pondering its effect on the temperature in the house - and there seems nothing written about this that I can find. Plainly when the water evaporates energy is ...
- 1
0
votes
1
answer
47
views
Difference between Kopp-Neumann and Dulong-Petit law?
So this is basically a follow-up to this question: How many degrees of freedom does the water molecule have?
I've done some further research and found that the main difference between Dulong-Petit and ...
- 73
1
vote
1
answer
51
views
Is it possible to use a water molecule's expansion/contraction effect with heat as a motor?
When water molecule is cooled, it is well known that it expands:
That's the reason the rocks in the desert explode in the cold of the night: the rocks have water inside that expands with cold and ...
- 113
0
votes
2
answers
80
views
Is it possible to make large waves from perfectly timed single drops of water?
Assume I have a hemispherical container of water and an eyedropper. Is it possible to add water to the container one drop at a time, such that each drop continues to add kinetic energy to the water?
...
2
votes
1
answer
161
views
Will adding salt to already boiling water made it stop boiling when under new boiling point elevation?
There is a so common understanding (IMHO misunderstanding) that you don't add salt to water on the beginning but later to make cooking faster. Ignoring the fact that the difference of boiling points ...
- 21
1
vote
1
answer
103
views
How would I calculate the energy released during an average Old Faithful geyser eruption?
I am working on a comparison between the electrical energy our company saved through energy efficiency and the energy needed to "power" an Old Faithful (OF) eruption. I found an estimate ...
- 11
0
votes
2
answers
164
views
Cup of Tea - Luxury Item?
Some bloke was saying it costs about UK£1.80 to boil water in a kettle (for 4 people) to make a cup of tea. With all the energy crazyness going on at the moment, that is only going to get higher.
Is ...
- 111
0
votes
1
answer
92
views
Can you syphone water underwater by using outside water pressure?
If you have an underwater bio-sphere; is it possible, with the correct plumbing,to use the deeper outside water pressure to create a perpetual flow of water towards the shallow end where the pressure ...
7
votes
3
answers
1k
views
How is a calorie related to the Boltzmann constant?
A (small) calorie is defined as the energy needed to increase the temperature of $1g$ of water by $1\space K$, and its value is $1\space cal = 4.184\space J$.
How is this empirical value theoretically ...
- 193
0
votes
2
answers
27
views
Water in house to heat and cool? [closed]
In the summer, when it reaches 27c during the day I want it to be colder, and when it reaches 15c at night I want it to be warmer.
Is it possible to do some of this heating and cooling with water (...
- 113
-1
votes
1
answer
62
views
Generating hydrogen from moving water
I am a high school student and I have planned to participate in national innovation award of my country. In this competition, prototype of innovation is needed. I have created a design but I lack ...
1
vote
0
answers
23
views
When water is evaporated and the particles with a little more energy breaks away, Why do the molecules left have less motion?
From Feynman's Six easy pieces:
Then a molecule leaves it is due to an accidental, extra accumulation of a little bit more than ordinary energy, which it needs if it is to break away from the ...
- 21
1
vote
1
answer
46
views
Can hydrogen be generated from flowing water?
Imagine water (water is made conductive using salt) flowing at a great speed is passed through a high magnetic field.
Then due to changing flux , can we induce electric current in water? If electric ...
1
vote
1
answer
95
views
Flame changeing water temp faster when boiling as opposed to heating it up
Cooking beans I noticed that, after the beans came to a boil, they reacted much more quickly to the turn of the dial than cold. I'm wondering if the water an everything else is more sensitive and ...
- 13