%It is presumed that QuickField is already started, the problem coil.pbm is opened.
%The plunger is placed in x=0 position

%relay parameters
x_out = 0.010;       %pull out position. m
x_in = 0.006;        %pull in position, m
m_mass = 0.0045;     %plunger weight, kg
k = 4;             %spring constant, N/m
x_spring_free = 0.015;     %spring free would be position, m

%initial conditions
t_time = 0;         %time, s
x_position = x_out;  %plunger position, m
v_speed = 0;        %plunger speed, m/s

%integration time step, s
dt_time_step = 0.005;
%maximal integration time, s
max_time = 0.2;

%plot initial position
plot(t_time,x_position,'-or','MarkerSize',2);
hold all

while (t_time<max_time) && (x_position>x_in)
%electromagnetic force    
    theForce = getQfForceX(x_position);
%add spring force    
    theForce = theForce + (x_spring_free - x_position)*k;
%calculate acceleration and speed
    v_speed = v_speed +  theForce/m_mass * dt_time_step;
%calculate plunger position
    x_position = x_position + v_speed * dt_time_step;
    t_time = t_time + dt_time_step;
%plot x-position
    plot(t_time,x_position,'-or','MarkerSize',2);
    hold all
end
%add axis labels and title to the plot
xlabel('Time t, sec.');
ylabel('Position x, m');
title('Plunger position vs. time');