Create a new document in Flash. You can take a look at my default document settings.
Select the Oval tool & make a perfect circle by holding ALT while you drag.Place that circle out of your play screen.
Click once on your ball and press F8 to convert shape into graphic. That step will get you better results in your animations.
Create a new layer & right click (CRTL+click for Mac) & select properties. Select Guide, click OK. Return to your new layer and select the the Pen tool.factoring You will need to draw a split-curved line. Take a look at the sample below.
Create a new layer & right click (CRTL+click for Mac) & select properties. This Time Select guided. Click on your ball and drag its center onto your guid line.
Insert Keyframe at 20 & 50 on the Ball Layer. Insert a keyframe at 50 on the guide layer.
Here comes the Gravity "effect". Click on the first frame of the ball layer. In you main pannel, select Tween: Motion and set the erase like mine
Click on the frame 20 of the ball layer. In the main pannel again, select Tween: Motion and set the erase like mine.
Click on the frame 50 of the ball layer & drag your ball to the end path (centered).