I am planning to create app/apps to work with Impact Earth http://purdue.edu/impactearth and I'll probably need some help in interpreting some of the formula from their documentation.
if somebody would possibly willing to help?

Of coursse I give information in credits about every person who will help me.

The beginning is simple <- rest is a black magic :D

We have 6 input params:
1) L0 - size of object

2) Pi - dentisity of object:
a) ice - 500-1500 kg/3
b) rock - 2000-3000 kg/m3
c) iron - 8000 kg/m3

3) V0 - velocity of object

4) θ Theta - angle of hits

5) Pt - target type:
a) solid rock - 2500 kg/m3
b) crystal rock - 2750 kg/m3
c) water - 1000 kg/m3

5c) for Pt = water we need Dw as water deep

6) r distanse from hit