All Questions
13
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'...
- 12.5k
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....
- 53
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 ...
- 31
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 ...
- 534
-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
views
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
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
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
4
votes
5
answers
2k
views
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
views
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!
- 933
0
votes
3
answers
5k
views
Why can you lift more weight with bad form?
Sorry for the lack of academia behind the subject of the question, however I'm trying to prove a friend wrong.
He says that bad form with a deadlift will not allow you do more weight and he's doing ...
0
votes
3
answers
315
views
Work power and energy
When you push your bicycle up on an inclined the potential energy of the bicycle and yourself increases. Where does this energy come from?
user60881
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 ...
aaron