README.md

# Paper_Airplane_Challenge_1
the first in class design challenge 2/20/2017

function dudt=phugoid(t,u) 
g = 9.81 ;    % gravity in m s^(-2)
v_t = 5.5;   % trim velocity in m s^(-1)   
C_D = 1/5.2;  % drag coefficient --- or D/L if C_L=1
C_L = 1 ;  % for convenience, use C_L = 1
pi = 3.1415926;

v = u(1);
 theta = u(2);
 x = u(3);
 y = u(4);
  dudt =  [-g*sin(theta) - C_D/C_L*g/v_t^2*v^2, -g*cos(theta)/v + g/v_t^2*v, v*cos(theta), v*sin(theta)]';
  
end  %ode45