# Homework Help: Free fall equations Sky diver Felix need some help please

1. Oct 9, 2012

### najat

free fall equations ...Sky diver Felix :) need some help please

hi :)

OK..i tried to use the equations below to evaluate the distance or the time at which felix will reach the speed of sound ...but i failed ..i need some help:
here what i did:

first i neglect the air resistance , but the result was unreasonable so i used these:

i assumed that :

m=weight of felix=70 kg
h=the height=36000 m
k=air resistance=0.24 >> i think "k" during the falling and by the time will be increased to 70

the result was :
t=2.7*10^56 sec :0
v=53 m/s :(

i don't know what i miss here ! so if someone will help me i will be so tankful ..

2. Oct 10, 2012

### najat

Re: free fall equations ...Sky diver Felix :) need some help please

hi ..
any body have any idea :(

by the way this is not for home work , it just a question pop up to me and i want to solve it , but it has been moved here :)

3. Oct 11, 2012

### CWatters

Re: free fall equations ...Sky diver Felix :) need some help please

Just for info...

http://hypertextbook.com/facts/JianHuang.shtml

Scroll down that page for the maths.