The x-axis is horizontal, positive to the right.
The y-axis is vertical, positive up.
Note that the drawing area is re-scaled whenever the initial speed is changed, but not when the launch angle is changed. For a fixed initial speed, therefore, you can easily see how the path depends on the launch angle.
Here are a few things to try:
Created by Andrew Duffy, Boston University Physics Department.
Last update September 1, 1998