# How can you land safely when falling from free fall?

1. Nov 17, 2015

### nofrills

Hi i'm trying to explain how this cartoon is physically impossible

I know its impossible from common sense, but i dont 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?

2. Nov 17, 2015

### davenn

hi there
welcome to PF

look at the terminal velocity equation here ...

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

and assuming the same person / object falling of a given mass and area, experiment with values of 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 landing

cheers
Dave

3. Nov 17, 2015

### Dr. Courtney

At terminal velocity, air resistance balances gravity. For most people in free fall, this is about 125 mph.