Help me with Physics please!

Hey im using Playmaker and I want to make by ball slow down when its in motion how do i do this? Would I use the details in Rigidbody?

It’s generally bad idea to interfere with existing physics simulation system, what you should do instead is write your own behaviour for specified object.
Start reading here Unity - Scripting API: Transform.Translate

To make your ball slow down add drag.
Your ball sphere has a component name Rigidbody with mass and drag
While your game is playing try to add drag to find the value you need.
Then when you stop the game the value will return to 0.
So now in drag, you can set the correct value.