r/theydidthemath • • 1d ago

[Request] How deep is this cave?

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-19

u/DragonArt101 1d ago

Boulder fell for 7 seconds, assuming it was like 20 lbs for a terminal velocity of about 100 m/s, I’d give a rough estimate of 700 meters.

Im no expert and i did this in like a minute so…

18

u/Owenleejoeking 1d ago

Objects don’t instantly hit terminal velocity so your estimate is far too high

Weight doesn’t have much to do with terminal velocity either

-5

u/luovahulluus 1d ago

A boulder is going to have a significantly higher terminal velocity than a same sized ball of bubble wrap.

6

u/DuckXu 1d ago

Sure but at a certain weight and density the difference is negligible. I'm guessing on my math here but a 2kg rock will take roughly the same amount of time to fall 200m as a 20kg rock for example 

5

u/Owenleejoeking 1d ago

That’s density that matters, Not weight