How to control the motion curve?

Dear all,

I want to do a effect like a ball move forward then decelerate a bit then accelerate again.
I know there’re ease out and ease in but they will make the ball stop moving!

I want to customize the motion curve, any easy way?

Have you seen this tutorial?
Sorry, the tutorial wasn’t categorized so it wasn’t shown on tutorials page of wiki:


Thank you very much. Should have check that out first. I am still learning to use synfig…very slowly.