"Index exceeds the number of array elements" Spring Mass Damper System

I am getting "Index exceeds the number of array elements" error while solving a Spring Mass Damper System with unit step input using Euler Integration. Here is the code:

clc
clear all
m = 5;
c = 0.5;
k = 1;
%input
h = 1/60;
t_fin = 50;
N = t_fin/h;
%Initial Conditions
t(1)=0;
x(1)=1;
v(1)=0;
u(2:51)=2;
%loop
for i=1:N
t(i+1) = t(i)+h;
x(i+1) = x(i)+h*(v(i));
v(i+1) = v(i)+h*(u(i)-(c/m)*v(i)-(k/m)*x(i));
end

figure(1)
plot(t,x)
figure(2)
plot(t,v)

Answer 1

[David Hill]

for i=1:N
  t(i+1) = t(i)+h;
  x(i+1) = x(i)+h*(v(i));
  v(i+1) = v(i)+h*(u(i)-(c/m)*v(i)-(k/m)*x(i));%appears your problem is with u
end

Loop goes from 1 to 3000, yet u is only defined from 1:51. Once the loop gets to i=52 it will error.

[Onat Aytac]

Yes, the problem was u. Thank you!