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, José 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