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Q: If you are in free fall and your parachute fails, but you have a Slinky with extremely convenient mass, tension, etc., would it be possible to save yourself by throwing the Slinky upward while holding on to one end of it?
Randall’s response: A picture of someone attempting the experiment, without explanation.
My response: Um…no. There’s a little something called conservation of momentum. If you throw the Slinky upward, you’ll be pushing yourself downward even faster by Newton’s Third Law, which kind of defeats the purpose. Even if the Slinky started pulling you back up by its spring force, it would lose energy, and it wouldn’t be able to slow you down any more than if you tried to bleed off your momentum by throwing it downward in the first place. To do that, however, you would have to cancel out your momentum of falling—in other words, apply the same force as throwing your own weight at your terminal velocity of about 120 miles per hour. Unless you’re a superhero, that’s not going to work so well, and if you are strong enough to do that, you’re probably also strong enough to withstand the landing anyway.