spring_mass(F,m,k,w​,t,y)

Mechanical resonance is the tendency of a mechanical system to respond at greater amplitude when the frequency of its oscillations matches the system's natural frequency of vibration .
clear all
clc
y0=[0;0];
tspan=[0 5];
k=2e3;
m=2;
F=1;
w=sqrt(k/m);
[T,Y]=ode45(@(t,y) spring_mass(F,m,k,w,t,y),tspan,y0);
plot(T,Y(:,1));