All Questions
Tagged with everyday-life biophysics
52
questions
5
votes
3
answers
377
views
Why do most fish wiggle their tails side to side, and not up-down?
Is moving a vertical fin side to side more efficient than moving a horizontal fin up and down in water for fish locomotion? The answer might lie in how fish propel themselves using vortices, but I don'...
- 11.7k
182
votes
14
answers
77k
views
Why does holding something up cost energy while no work is being done?
I read the definition of work as
$$W ~=~ \vec{F} \cdot \vec{d}$$
$$\text{ Work = (Force) $\cdot$ (Distance)}.$$
If a book is there on the table, no work is done as no distance is covered. If I ...
- 817
3
votes
1
answer
95
views
Bicycle Uphill vs. Walking Uphill
When bicycling uphill, I have noticed it takes a enormous amount of effort compared to just walking uphill. However, when on level ground, bicycling seems to take considerably less effort than walking....
- 41.1k
0
votes
0
answers
24
views
Effects of chromatic aberration in the human eye
Due to metamerism, many different light spectra can be used to show a white colour.
If I understand it correctly, it is even possible to make white light by combining only two monochromatic light ...
1
vote
0
answers
33
views
What was Grant Holloways top speed in his 12.81s 110m hurdle run using kinematics? [closed]
I am a currently a introductory biophysics student and I am attempting to analyze Grant Holloway's 12.81s 110m hurdle run. I thought the best approach would be to break the run into stages due to the ...
- 207k
1
vote
1
answer
1k
views
What takes more energy? Walking up stairs or ramp over the same height?
Often when we go hiking, we encounter two kinds of paths whenever we have to cover elevation. We either go up via stairs or via walking up a ramp. Sometimes both are available side to side. And it's ...
- 2,270
29
votes
10
answers
10k
views
What's the difference between running up a hill and running up an inclined treadmill?
Clearly there will be differences like air resistance; I'm not interested in that. It seems like you're working against gravity when you're actually running in a way that you're not if you're on a ...
- 47
-4
votes
3
answers
3k
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Life and Death, and Energy Conservation
Humans are born and they die. When we are born, is energy created? Or is it just some amount of energy that our mother gives us? Doesnt she take this energy from the surroundings? If so, then when we ...
1
vote
5
answers
18k
views
Lifting and putting down a weight
A man in a gym lifts a weight and then puts it down where it was before.
What can be said about the work done by the man to the weight?
Can it be equal in absolute value to the work made by the ...
- 673
2
votes
3
answers
6k
views
Why the pressure of atmosphere doesn't crush you when you e.g. walk outside?
Why the pressure of atmosphere doesn't crush you when you e.g. walk outside? I mean the density of air is $1.26 kg/m^3$, so with $100 km$ above us, it exerts much pressure on you when you walk outside....
- 111
-1
votes
2
answers
211
views
Can humans feel artificial light? [closed]
I know humans can feel sunlight - even blindfolded, it's easy to tell if one is in the noon sun or indoors. However, I don't know about artificial light. Can humans feel sufficiently harsh artificial ...
- 15.2k
3
votes
1
answer
359
views
For weighted pull ups, how does positioning the weight below the hips (eg a dip belt) make the motion harder than when placed on the back (eg a bag)?)
I have been doing pull-ups for a while and decided to recently transition into weighted pull-ups for more growth. When gathering advice, I discovered that placing a weight between the legs, with the ...
- 6,621
33
votes
11
answers
12k
views
Why does running spend more energy than walking?
The study energy expenditure of walking and running concludes that running spends more energy than walking.
My understanding is that although running makes one feel more tired, that only indicates ...
- 2,241
0
votes
2
answers
2k
views
Atom or Cell? Which is the basic unit of life? [closed]
As it is said that everything in this universe is made up of atoms and molecules and atoms are called the building blocks of matter. But then why the cell is called the basic unit of life, why not ...
- 60.3k
0
votes
2
answers
69
views
What scientific evidence is there for the definable real world quality of redness independent our perception? [closed]
With light poise and counter-poise, Nature oscillates within prescribed limits. Yet thus all arise the varieties and conditions of the phenomena which are present to us in space and time. - Goethe
...
- 32.9k