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18

Strength / weight is a funny thing. The stress on a long thin rod (like an ant's leg) is limited by the Buckling strength which is given (for rod that can freely rotate at each end) by $$F = \frac{\pi^2EI}{L^2}$$ where $I$ is the second moment of area which scales with $r^4$ - so $$F \propto \frac{r^4}{L^2}$$ So when you make an object 2x smaller, the ...


53

Strength is proportional to surface area divided by volume, but since volume is directly proportional with mass and i can't get an accurate density (i am guessing approximately both for mass and size.), i will use mass instead. According to Wolfram Alpha, the average mass of human body is 70 kilograms. The surface area of a person weighing 70 kg with a ...


40

I think the answer has less to do with their construction and more to do with their smaller size For more information lookup Scaling Laws. Basicly the mass of a object scales as it's size cubed so a ant 10 times the size will be 1000 times heavier. But the strength of an organism depends on the cross sectional area of muscle (I've heard this somewhere, not ...


0

Let's get one thing out of the way: The work done against gravity is the same whether you are running on an inclined treadmill or running (at the same velocity) up a hill. You see this by considering the motion in the frame of reference of the runner - you can't tell whether you are moving up or the hill is moving down. Yet the treadmill is easier for two ...


0

I think the most significant difference between work done on an inclined treadmill and work done on a real incline is the gain in potential energy on the real incline. There is no real delta mgz on a treadmill, whereas if you fell back to your starting height from a real incline, you'd certainly notice a large amount of stored energy being turned into ...


1

Let's assume the drag coefficient for the borrowers is the same as that for a human. The drag force depends on the velocity and the area, which will be 144 times smaller, if your assumption of " twelve times smaller in each dimension" is correct. \begin{align} F_D &= 0.5 \rho V^2 S C_D \\ &= 0.5 \rho C_D V^2 \frac{S_{\rm human}}{144} \\ \end{align} ...


1

One answer lies in utility and the evolutionary origin of our eyesight. Our eye is basically the same as that of a fish. Water absorbs red light. It absorbs near infrared even more strongly. Fish didn't evolve the ability to see in the near infrared because this strong absorption would make that capability rather useless. Near infrared would also be rather ...


3

My previous answer was off topic because, as a comment says, it was about the far infrared, not the near, as you asked. I still leave it for those interested, at the end of this new edited answer. The problem is that water vapor has a strong absorption in the on the near infrared, so the actual light that comes from the sun has much less power than in the ...


1

There are many variables that come into play in an armwrestling match, but one answer as to why a person with a larger hand and wrist has an advantage in armwrestling has less to do with strength, and more to do with leverage. In armwrestling, you and your opponent lock hands and attempt to pin each other to a pad on either side of the table. To pin your ...



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