%
% free body diagram 2
%
close all
t = 0:.01:1;

mx = cos(2*pi*t)/2;
my = sin(2*pi*t)/2;

plot([0 0],[-.6 -1.5],'k','linewidth',2)
hold on
plot([-.1 0],[-1.3 -1.5],'k','linewidth',2)
plot([.1 0],[-1.3 -1.5],'k','linewidth',2)
text(.2,-1,'y_1','fontsize',16)

plot([0 0],[.6 1.5],'k','linewidth',2)
plot([-.1 0],[1.3 1.5],'k','linewidth',2)
plot([.1 0],[1.3 1.5],'k','linewidth',2)
text(.2,1,'f_2','fontsize',16)

plot(mx,my,'k','linewidth',2)
text(-.2,0,'m_1','fontsize',16)
plot([.6 3/2],[.2 .2],'k','linewidth',2)
plot([1.3 1.5],[.3 .2],'k','linewidth',2)
plot([1.3 1.5],[.1 .2],'k','linewidth',2)
plot([.6 3/2],[-.2 -.2],'k','linewidth',2)
plot([1.3 1.5],[-.3 -.2],'k','linewidth',2)
plot([1.3 1.5],[-.1 -.2],'k','linewidth',2)
text(1,.5,'y_2','fontsize',16)
text(1,-.5,'f_1','fontsize',16)

% 2nd mass

s = 4;

plot(s+[0 0],[-.6 -1.5],'k','linewidth',2)
plot(s+[-.1 0],[-1.3 -1.5],'k','linewidth',2)
plot(s+[.1 0],[-1.3 -1.5],'k','linewidth',2)
text(s+.2,-1,'y_3','fontsize',16)

plot(s+[0 0],[.6 1.5],'k','linewidth',2)
plot(s+[-.1 0],[1.3 1.5],'k','linewidth',2)
plot(s+[.1 0],[1.3 1.5],'k','linewidth',2)
text(s+.2,1,'f_4','fontsize',16)

plot(s+mx,my,'k','linewidth',2)
text(s-.2,0,'m_2','fontsize',16)
plot(s+[.6 3/2],[0 0],'k','linewidth',2)
plot(s+[1.3 1.5],[.1 0],'k','linewidth',2)
plot(s+[1.3 1.5],[-.1 0],'k','linewidth',2)

plot(s-[.6 3/2],[0 0],'k','linewidth',2)
plot(s-[1.3 1.5],[.1 0],'k','linewidth',2)
plot(s-[1.3 1.5],[-.1 0],'k','linewidth',2)

text(s-1,.4,'y_2','fontsize',16)
text(s+1,.4,'f_3','fontsize',16)
axis equal
axis off
hold off
