I am not good at Physics so please bear with me. I am trying to understand harmonics and in order to do that I thought its best to ensure my understanding of the equations of motion is correct. To do this I tried to model a mass vibrating on a frictionless surface with restoring force from a spring when acted on by a force F. The parameters are as follows:
M = 5 kg (Mass) F = 10 kN (Initial force) k = -1kN/m (Spring constant)
I expected the plot of displacement against time to be uniform i.e without dissipation (or no damping). However, the result shows that the displacement are increasing. Have I made a mistake, if not, could someone explain the phenomena.
Algorithm is as follows: F = 10kN m = 5kg k = -1kN/m initial acceleration, a0 = 10/5 = 2 m/s Assuming displacement is positive to the right At t = 0, u = 0 v = 0 s = 0 dt = 1 a0 = 2 ar = 0 anet= a0-ar While (t<100), ds = u*dt + 0.5anet*dt^2; s = s + ds; v = u + anet*dt; t = t + dt acceleration by restoring force, ar= (k*s/m); updating net acceleration, anet = anet + ar; //K is already negative Next;
Update: I plotted the same graph at different time steps.