Playblasts are Maya's way of creating a preview of your animation that runs in real time and is much faster to output than a render. When playblasting motion that somebody else is going to review (for both turn-in and production), you will want to take extra care to make a "clean" playblast. The steps below will help you do this.
First, select the viewport you want to playblast from. In the case of your bouncing ball obstacle course it should be the panel with the orthographic "render_cam" camera. In the Show menu there will be a long list of object types that can be shown or hidden. For now you just need to uncheck the grid and NURBs Curves. Unchecking NURBs Curves will hide the ball rig controls.
And though you have a preset camera for this assignment, this will not always be the case in the future. In those instances make sure that the camera is a reasonable distance from your animated object or character. It shouldn't be so far away that you can barely see the motion, but it also shouldn't be so close-up that part of it gets cut off.
Next, go to Window → Playblast options. The main options that need to be changed are listed below.
You should now be ready to playblast. The settings should stay the same while the scene is still open, so you don't need to constently revisit the options. A quick way to spit out a playblast is to right click the timeline and choose Playblast... at the bottom of the menu.