forward euler-odes
显示 更早的评论
d^2/dt^2+g*R^2/(R+x)^2
x(t=0)=0
dx(t=0)/dt=750 m/s
FORWARD Euler dt=0,1s
is this correct to find the x in t=10s.
回答（1 个）
You should plot x and y against t to see whether Euler forward is maybe unstable for a time stepsize of dt = 0.1 and that this was the task of the exercise. At least the MATLAB integrator ODE45 gives a different result.
g = 9.81;
R = 6.37e6;
fun = @(t,y) [y(2);-g*R^2/(R+y(1))^2];
tspan = [0 10];
y0 = [0 750];
[T,Y] = ode45(fun,tspan,y0);
Y(end,:)
plot(T,Y)
类别
在 帮助中心 和 File Exchange 中查找有关 Numerical Integration and Differential Equations 的更多信息
2023-6-19
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
