d2jsp
Log InRegister
d2jsp Forums > Off-Topic > General Chat > Homework Help > Iso Position As A Function Of Time Of A Falling > Body With Resistance Equal To V^2
Add Reply New Topic New Poll
Member
Posts: 54,265
Joined: Aug 22 2004
Gold: 6,069.00
Jul 6 2013 07:18pm
There is an exact equaition that inolves speed of an object falling with respect to time. It involves e, etc...
Member
Posts: 16,662
Joined: Nov 24 2007
Gold: 15,245.00
Trader: Trusted
Jul 7 2013 05:01am
Post the question, or pm.
Member
Posts: 14,000
Joined: Apr 6 2009
Gold: 140.07
Jul 7 2013 02:19pm
Sounds like you want to use Lagrangian.

But like feanur said post the question or we cant really help.
Member
Posts: 16,144
Joined: Mar 27 2008
Gold: 14,618.00
Jul 8 2013 04:10am
Quote (feanur @ 7 Jul 2013 12:01)
Post the question, or pm.

imo the question is very well given.
Quote (khemist @ 7 Jul 2013 21:19)
...or we cant really help.

maybe not you two, but I can help.

skip steps 4/5/6 if you don't want the air resistance.

0) position is integration of speed (and starting position)
1) so you want the speed.
2) the speed is the integration of the acceleration (plus the starting speed)
3) the acceleration is calculated by the force and the mass: a = F/m (where m is constant)
4) the force F is the difference of gravity-force (Fg = m*g) and the air resistance Fa
5) the air resistance is quadratic. the formula is either given or you can take it from wikipedia (also shape-dependant of the mass)
6) Fa = c*v^2 (c is just a constant that replaces some constants...)
7) now combine my formulas (should be easy)
8) notice that this is a differencial equation. (if you have air resistance, its not solvable without numerics cuz of the quadratic term inside.)
9) optional donate
10) profit
Go Back To Homework Help Topic List
Add Reply New Topic New Poll