Hi guys! I have to write a program to simulate a jump with a parachute, actually i have written a part without opening the parachute. But if I try running it I keep getting this error:

My source code:Quote:

??? Error using ==> plus

Matrix dimensions must agree.

Error in ==> parachute at 24

s=[s,s+ds];

I'd be very happy if someone could help me.Code:`clear all`

m=90; % mass of jumper

cm=0.43; % cw-Value (value of the air-resistance)

Am=1; % "surface area" of jumper

g=9.81;

roh=1.2929; % density air

dt=1; % at which interval values will be calculated

h=2000; % total height

k=(cm*Am*roh)/2; % constant part of the formula for acceleration with air-resistance

a=g; % a at beginning

v=0; % v at beginning

t=0; % t at beginning

s=0; % s(height jumper already passed) at beginning

% jump's duration

ti=h/(sqrt(2*m*g/(cm*Am*roh)));

ti=floor(ti);

for t=1:dt:ti

ds=v*dt;

s=[s,s+ds];

a=[a,g-(k/m)*v^2];

dv=a*dt;

v=[v,v+dv];

t=[1:0.1:ti];

end

plot(t,v,'b')

grid on

hold on

plot(t,a,'r')

grid on

hold on

Sorry if my English isn't really good at some points, even so I hope you can understand it :D

Best regards,

unique