plotting two objects in the same figure

I have a question please help me out on it. I want to plot two object. the first object is thrown at a hight until it reaches its highest point, at that time the second object realized at that height that has a free falling object, and the first object continue its pass until both of them hit the ground. both both must be in the same loop, and I don't know how to show both of them at the same time and the two loops that are inside of each other be independent.

Answer 1

[Image Analyst]

Put hold on in between the plots:

plot(..................
hold on;
plot(..................

See my attached projectile demo.