two questions that i would like answers

The question isn't about displacement, it's about weight. Boyancy equals anti-gravity, and anti-gravity counters weight. Otherwise, fish couldn't swim, and hot air balloons couldn't fly.

Cheers

 

haha. I remember that one, now, from Mythbusters. I see your point. A gas can stay is a container. But it's still being displaced. When the foil craft falls...I think you know.

 

You got me. So do you think it still weighs 500 lbs or is it more?

 

never said it wasn't displaced, but it was simply possible for it to be displaced while staying in the same system.

 

I say it's still 500lbs. Can you weigh yourself when you are floating in a pool? No. So how can your weight increase that of the pool? (And you don't even have a swim bladder... haha)

Cheers

 

I guess that depends though. Say you have a 5g bucket of that gas, filled to the rim. Drop the foil in it. It floats on the top. Poor some of that gas on the foil. Now the foil takes up the gas's space in the bucket & the gas spills over the edge. Oops, my bad. It made t left the system.

 

now lets say gas in the bucket isn't filled to rim, but maybe 1 inch from the rim on a planet with no atmosphere but still enough gravity to hold the gas in the bucket. you slowly lower a rock in it that will only displace enough gas to raise the level .5 inches from the rim. In that senario you won't lose any gas from the total system(bucket).

that same scenario would work on a planet with atmosphere, where the gas in the bucket is heavier then the atmosphere.

just like if you had 1 gallon of water in a 5 gallon bucket and add a small rock, you don't lose any water from the system(the bucket).


If I can teach the younger generation some science I feel I have done my job.

 

So your telling me that if I fill a bucket /tank up with water to where it weights 30 lbs and I put 10lbs of floating golf balls in that bucket and it doesnt displace any water that the bucket still weights 30lbs......: That doesnt make any sense. Hot air ballons float due to the hot air being trapped in the balloon. It still weights the same but it has more uplift from the hot air than the down pull of gravity. Hence the reason it goes up.

 

haha. I see your point but I think he means, yes, it would be displaced.

......Ugh now I am confused.

 

I HAVE to use this one in my signature. The screaming trees are giving me a headache. Where is the NasaGeek??