NTNUJAVA Virtual Physics Laboratory
Enjoy the fun of physics with simulations!
Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

Information about this web site => Request for physics Simulations => Topic started by: jeff_forssell on October 11, 2007, 02:12:27 pm



Title: *v^2 in a physlets formula for air resistance
Post by: jeff_forssell on October 11, 2007, 02:12:27 pm
I was very excited to see " Request for physics Simulations" as a forum.

But disappointed to see nothing here!

I have been trying to find a Physlet that had a proper air resistance function but only found ones with k*v and If I tried to change them to k*v^2 they didn't work. Anybody got any ideas?


Title: Re: *v^2 in a physlets formula for air resistance
Post by: Fu-Kwun Hwang on October 11, 2007, 09:15:29 pm
I just add this new forum a few days ago. So you are the first one to ask for new simulations.
Actually, I have created one with k*v2 many years ago. You can find it at Projectile Motion with Air Drag (http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=145.0).
In the above simulation I have created, you find find I use a very large initial velocity and the scale was in unit of km.

Due to your request, I am going to create a new which you can select the air resistance to be either k1*v or k2*v2.
k1 and k2 are not the same dimension. And if you just changed the formula from k*v to k*v2. Because the air resistor become so large, it will stop very shortly. And you might not see the object moving. (May be that is the reason why you did not see the effect)
I will post it soon when it is done.


Title: Re: *v^2 in a physlets formula for air resistance
Post by: Fu-Kwun Hwang on October 11, 2007, 09:52:56 pm
The formula for the air resistance in the following applet is k1*v+k2*v2.
If you set k1=k2=0, then there is no air resistance.
If you set k1=0 or k2=0,then you can study different cases.
I would suggest you starts with the default setting, k1=k2=0. (The object will move out the default range, the scale will change automatically- you can adjust the scale from the slider at the right edge)
Then change k1 to either 0.01 or 0.1 and check out the effect.
Then set k1=0 and k2=0.001 , 0.01 or 0.1 and check out the effect.
(It will remember the last 5 traces) Enjoy it.
-*-


Title: Re: *v^2 in a physlets formula for air resistance
Post by: Fu-Kwun Hwang on December 09, 2007, 12:05:37 pm
This is an image for k1=0, 0.1, 0.01

(http://www.phy.ntnu.edu.tw/ntnujava/snapshotejs/airdrag_2_20071209130410.gif)


Title: Re: *v^2 in a physlets formula for air resistance
Post by: jeff_forssell on May 07, 2009, 03:27:07 pm
I haven't been back to the forum for quite a while. I see that now there is a lot of new stuff in this "request for sims" forum.

I did finally figure out how to get a proper k*v^2 into some Physlets I was working on.

Wondering maybe if this might be the place to try to start a physlet and PAD forum.


Title: Re: *v^2 in a physlets formula for air resistance
Post by: lookang on May 07, 2009, 04:01:18 pm
http://www.phy.ntnu.edu.tw/ntnujava/index.php?board=24.0
Physlet builder (Create your own simulation)


Title: Re: *v^2 in a physlets formula for air resistance
Post by: massan on October 14, 2009, 03:27:12 pm
A very interesting simulation, I will understand more