# Tag Info

## Hot answers tagged hard-science

### Can you use plants as substitute for missing metals/elements?

No Those are some zinc rich beans if they would work... Your body only needs trace amounts of these elements, too much and you could die, too little and you get serious health problems (Toxicity is in ...
• 894

### Could a desert animal recycle ammonia into protein to avoid urinating?

Half a frame challenge: Use uric acid. Forming uric acid (birds, reptiles) rather then urea(mammals) is a viable option to reduce water output upon excretion. Uric acid is more expensive metabolically ...
• 4,381
Accepted

### Could a desert animal recycle ammonia into protein to avoid urinating?

The first and obvious problem is that urination removes many toxic chemicals from the body, only two of which are ammonia or urea. At best, this plan can reduce the rate of urination by reducing how ...
• 1,662
Accepted

### How much lift would this multi-winged flying ship generate at 100 kph?

Even if you exclude turbulence issues, about 78 tons The exact lift coefficient of the DG Flugzeugbau DG-800 is really hard to find, but I was able to find data on a number of similar wings and found ...
• 75.4k

### Gravity-powered cannonballs for mountain dwellers

Being gravity a conservative force, we know that the maximum velocity you can get dropping from a given height is $v=\sqrt{2gh}$. That maximum velocity will be reduced by a part due to losses. What ...
• 262k

### Gravity-powered cannonballs for mountain dwellers

Some quick googling gives a vertical terminal velocity of a rigid spherical object of ~ 70 Mph (Source ) - bearing in mind that is straight down. But that site also has a calculator, so... Using a ...
• 6,419
1 vote

### Gravity-powered cannonballs for mountain dwellers

45 degrees is only good if you have no drag. With drag present, the optimal angle is lower. Reference: artillery tables based on farthest point of reach. An overview of what is in them could be read ...
• 3,316
1 vote

### What is the ideal day length for extreme weather?

Venusian Days and the Runaway Greenhouse Effect: I think the problem with the question is that there are many factors that can create extreme weather. I'm going off my memory of astronomy class so ...
• 111

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