4
votes
0answers
137 views

Do human bodies give off a consistent but unique radiation/electromagnetic/energy signature?

Is there any facet of the energy emitted by a human body that is consistent and unique - like a fingerprint, but a signal that could be detected by a remote device?
0
votes
1answer
204 views

Calories burned doing 1 squat [closed]

To calculate the calories burned doing 1 squat, wouldn't it simply involve the distance that your center of mass is moving and your weight? I read some other article that said your legs act as levers, ...
16
votes
2answers
887 views

Why can't Humans run any faster?

If you wanted to at least semi-realistically model the key components of Human running, what are the factors that determine the top running speed of an individual? The primary things to consider would ...
4
votes
2answers
6k views

How efficient is the human body?

This question sort of comes to mind when hearing how efficient an internal combustion engine is turning chemical energy in mechanical energy (something like 20-40%) with lots of excess heat. As an ...
0
votes
2answers
158 views

How much time can I power my laptop by eating one dessert?

Random question that popped into my mind after a 4-hours power outage. Let us assume that I am eating an extra dessert (250 kcal) and that I am using a bike and a generator to power my laptop (it ...
1
vote
0answers
39 views

Is energy applied by the muscle when it holds a body in the air? [duplicate]

Possible Duplicate: Why does holding something up cost energy while no work is being done? We all know the following Newtonian formulas: PotentialGravitationEnergy=m*g*h Kinetic Energy = ...
0
votes
1answer
109 views

People eating and gaining energy

Let's say we have 100 grams of chocolate which has 571 kilocalories (so it's about 2.4 megajoules) and we have barbell which weights 100 kilograms and need to lift it to 0.5 meters height. So how ...
6
votes
2answers
1k views

How are the calories in food calculated?

This is intended to be a fun question. Calorimetry used for calculating the heat generated from chemical changes has been around for centuries, however, I suspect the process for calculating food ...
35
votes
8answers
6k 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 ...