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

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

plot([-3/2 -.6],[0 0],'k','linewidth',2)
hold on
plot([-1.5 -1.3],[0 .1],'k','linewidth',2)
plot([-1.5 -1.3],[0 -.1],'k','linewidth',2)
text(-1,.2,'y_j','fontsize',16)

plot(mx,my,'k','linewidth',2)
text(-.07,0,'m_j','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,.4,'y_{j+1}','fontsize',16)
text(1,-.4,'f_j','fontsize',16)

axis equal
axis off
hold off
