All Questions
Tagged with everyday-life biophysics
52
questions
5
votes
3
answers
377
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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'...
- 12.5k
3
votes
1
answer
95
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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....
- 53
0
votes
0
answers
24
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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
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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 ...
- 19
1
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1
answer
1k
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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 ...
- 111
-1
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2
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211
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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 ...
- 21.4k
3
votes
1
answer
359
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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 ...
- 31
33
votes
11
answers
12k
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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 ...
- 534
0
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2
answers
2k
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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 ...
- 231
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votes
2
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69
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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
...
- 107
0
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1
answer
48
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Has physics ever tried to explain how do we get "sensorial experiences"? [closed]
To be clear about what I mean with "sensorial experiences", let's take for example our visual experiences. Certainly, physics (and other sciences) explains a whole process which involves light ...
- 1,252
8
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11
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1k
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Is it more work to put more (apparent) effort to get the same outcome?
I was taking my dogs for a walk yesterday evening when this question occurred to me.
The two dogs were pretty enthusiastic about the walk and wanted to run on ahead, so the leads were taut and they ...
- 257
-2
votes
5
answers
6k
views
Why we can't jump without bending our knees?
I observed it while trying to jump from my bed with my knees straightened and I failed to do it. I want to ask whether it is with all of us our it may be a medical issue with me?
Why we can't jump ...
- 3,377
5
votes
2
answers
6k
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Why does a person carry more weight when sitting down?
Today, while shopping for a chair at a shopping mall, I saw this poster regarding the amount of weight a person is carrying when doing various activities. When standing upright, one carries 100% of ...
- 3,745
0
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1
answer
671
views
Motion of head during sneezing
When we sneeze, our head moves forward.
However since the air from our mouth moves forward with a high velocity, shouldn't the head should recoil backwards (like a gun, to conserve the momentum) ...
- 706
2
votes
2
answers
178
views
Newtonian Physics vs Metabolic Equivilant (MET) calculations
I am trying to help my daughter do her physics homework. Her assignment includes calculating Calories worked off while exercising.
The formula she is using is ...
- 131
3
votes
2
answers
475
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Human body as a measuring instrument
One can easily find descriptions of human eyes and ears used for measuring phenomenons. Finding what resolution do eyes have or what frequencies can human hear is no trouble. It is also seen in scales ...
- 59
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1
answer
2k
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The physics behind the Judo "hip throw"
Recently, I saw my friend, the Judo captain, easily defeated his much larger opponent with the famous "hip throw" as shown here. Upon researching, I found out that this throw can allow a weaker ...
- 3,745
67
votes
15
answers
22k
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Why is ascending some stairs more exhausting than descending?
I have been asked this question by school kids, colleagues and family (usually less formally):
When ascending a flight of stairs, you exchange mechanical work to attain potential Energy ($W_\text{...
- 831
1
vote
1
answer
3k
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experiencing vibration when in contact with my desk computer and a rubbing a friend's arm [closed]
I was with a friend sitting next to my desk computer, I put my hand on the computer and the other one on my friend who is in contact with the floor. The thing is that when I rub my hand on his arm we ...
- 41
1
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0
answers
48
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Do prescription glasses augment or mitigate the effect of the sun on the skin around the eyes directly beneath them (assuming no UV blocking coating)?
The question is about minus correction (nearsightedness), but would also be interesting to know how it differs for plus correction (farsightedness), cylinder correction (astigmatism), axis correction.
- 39
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0
answers
58
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How much heat do we lose perspirating?
How can I calculate the heat my body loses from perspirating? For example, X Jouls per liter of sweat.
- 151
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4
answers
6k
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How can we feel temperature?
Recently I watched a Youtube Video by
Veritasium
He said we are actually feeling the rate of heat transfer, not the temperature.
But how do we feel temperature?
How is temperature different from ...
2
votes
3
answers
1k
views
Why are ski jumpers slim?
Assuming perfect technique and material, how does the mass of a ski jumper affect the performance?
The higher potential energy of heavier jumpers could favour heavier jumpers, but then also friction ...
- 4,292
19
votes
5
answers
7k
views
How is it possible for other animals to have better night vision than humans, who can detect individual photons?
According to the Wikipedia article on night vision,
Many animals have better night vision than humans do, the result of one or more differences in the morphology and anatomy of their eyes. These ...
- 48.4k
0
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1
answer
334
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Are noise cancelling headsets safe? [closed]
Older microlight headsets such as the Lynx Micro System are modelled on ear defenders and physically attenuate the noisy cockpit environment by clamping hard onto your noggin. Most modern GA headsets (...
- 119
0
votes
0
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264
views
What are the possible dangers of removing the microwave shielding?
Would removing the shielding from a domestic microwave door allow the microwaves to cause damage to a consumer grade video camera, and if so, what damage would it cause?
- 183
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1
answer
685
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Electric discharge through my knuckle
In some particular days, it seems that my car is somehow at a different potential from the ground. When I get out my car and I wear my sneakers (that I think are better insulators than other kind of ...
- 1,764
4
votes
5
answers
2k
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Why is it so much easier to fall when walking down a slope?
When I walk uphill on an icey road, I almost never slip/fall. But if I walk downhill or even on a relatively flat road, I slip/fall frequently.
What is the physics reason behind this, and are there ...
- 57
18
votes
3
answers
10k
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Which requires more energy: walking 1 km or cycling 1 km at the same speed? [closed]
I feel more tired walking 1 km than cycling 1 km at the same speed. However when cycling I am moving the extra weight of the cycle along!
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