How can you land safely when falling from free fall?

AI Thread Summary
Air resistance must exceed gravitational force for a safe landing from free fall, and this can be quantified using the terminal velocity equation. Terminal velocity occurs when air resistance equals gravitational force, typically around 125 mph for a human. Increasing the density of the fluid or gas through which an object falls can enhance air resistance, potentially leading to a softer landing. Experimenting with different densities can provide insights into achieving a safe landing. Understanding these physics principles clarifies why certain cartoon scenarios are physically impossible.
nofrills
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Hi I'm trying to explain how this cartoon is physically impossible

I know its impossible from common sense, but i don't know how to explain it using physics terms So my questions are:

1) Does the air resistance force have to be much greater than the Fgrav to make you land safetly? If so how much does it have to be

2) What increases the air resistance?
 
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hi there
welcome to PF :smile:

look at the terminal velocity equation here ...

https://en.wikipedia.org/wiki/Terminal_velocity

it will answer your 2 questions

and assuming the same person / object falling of a given mass and area, experiment with values of
f7f177957cf064a93e9811df8fe65ed1.png
the density of the fluid/gas through which the object is falling.
Search the density for air and for say water and then for some other fluid/gas in between that would result in a terminal velocity that would give a soft landingcheers
Dave
 
At terminal velocity, air resistance balances gravity. For most people in free fall, this is about 125 mph.
 

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