Physics Examples/Help With Differentials

Posts: 1,066
Joined: 2004.07
Post: #1
I found a website ( that shows examples of 2D physics systems for a number of objects like springs and rigid bodies. It also explains things with some equations.

I'm currently trying to reproduce the single spring in my program (just learning some physics) but I am a bit rusty on differentials. I took very little calculus so I'm not very good with figuring out some of the things.

When it says
x'' = -k/m*x - b/m*x'
is that the same as
a = -k/m*x - b/m*v?

If so could I handle the position as follows (I intialized x = 4 and v = 0)?
    float m = .5; //mass
    float R = 2.5; //length of spring at rest
    float k = 3; //spring stiffness
    float b = .1; //damping constant
    float a = -(k/m) * x - (b/m) * v;
    v += a;
    x += v;

Thanks for any help.
Quote this message in a reply
Posts: 608
Joined: 2002.04
Post: #2
Nick Wrote:When it says
x'' = -k/m*x - b/m*x'
is that the same as
a = -k/m*x - b/m*v?
If x is the position function then yes, x'' would be acceleration.
Quote this message in a reply
Post Reply 

Possibly Related Threads...
Thread: Author Replies: Views: Last Post
  Porting examples from an introductory 3D book crazy_ut2k4 4 3,863 Feb 16, 2007 08:04 AM
Last Post: AnotherJake
  Bullet Physics Library / COLLADA physics viewer erwincoumans 14 16,297 Aug 12, 2006 12:59 AM
Last Post: Fenris
  NSAffineTransform Examples dancedrummer 2 6,538 Jul 1, 2005 09:34 PM
Last Post: dancedrummer