Updated: Oct 9, 2019
A student once asked me whether they weighed less in #water and more when they were falling through the #air. While it may appear that you weigh less in water, you actually weigh the same if you were standing on a set of #scales.
To prove it, if you were able to #submerge yourself in a tub of #water on a set of scales, you would find that the total weight (w) would be #equal to your weight (Wx) plus the weight of the water (Wy) : Wy+Wx=Tw
So while it may seem you weigh less in water, you are still exerting the same downward #pressure onto the scales.
Same goes if you are falling through the air, your #weight is constant and unchanging. If you weigh 80kg #falling out of the #plane, you will consistently weigh 80kg on the way down #displacing air on your way through.
In this case you’re #exerting downward pressure over a much larger area, but hypothetically if we could contain you (Wx) and the air (Wy) in a #container on a set of scales, the same total weight would be observed : Wy+Wx=Tw
So this leaves an interesting #question. Given we know anything #submerged in a fluid #displaces it, how much higher is the sea #level today due to #human made #submersibles? Is melting #ice the only thing we should worry about?