On 2002.02.21 12:57 Mike Mestnik wrote:
> What dose square of t have to do with falling objects?
Velocity does indeed varies linearly with time, so assuming a positive
up-oriented vertical axis:
v_i+1 = v_i + a * delta_t (1)
where
a = g = -9.8
delta_t = t_i - t_i-1
but the position doesn't vary linearly:
s_i+1 = s_i + v_i * delta_t + 1/2 * a * delta_t ^ 2 (2)
this law (2) results from the integration in time of (1) and is known not
only by any physics teacher but by any 14 year old physics student.
Doing
s_i+1 = s_i + v_i * delta_t
is just plain wrong because it's neglecting the last integration term, as
Bill Currie had previously noted.
> It's recursive addition (Multiplication), t * 9.8 = "speed at t".
> you might take the root of speed but only to find how long it has been
> falling
> (Incorrect thought because you would also have to account for initial
> velocity).
>
> if gravity acceleration = 900(the cvar) + gravity acceleration(One second
> ago)
> then you would have the correct equation then.
>
> I.E
>
> startfall() {
> my.nextthink = time + 1;
> };
>
> think() {
> my.v = (static float ga = 900 + ga) + my.v;
> my.nextthink = time + 1;
> };
>
> endfall() {
> my.v = {my.v(0), my.v(1), 0}; // Only set vertical speed :)
> my.nextthink = NEVER;
> };
>
> Is how a physics teacher might have coded it.
>
Regards,
Jos� Fonseca
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com
_______________________________________________
Dri-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/dri-devel
