By Katherine

This video shows techniques on how to pass the basketball around the court to each player. The law of conservation of momentum can be demonstrated when passing the ball. When you pass the basketball, the basketball to you is the system; its not isolated. There is a net external force on the system to keep you from moving backwards that changes the momentum of the system. If the ball to you system is isolated (let's say you are standing on frictionless ice) then you do move backwards when passing the ball. In this case, law of conservation of momentum does not apply because the system is not isolated. However, you can include the floor, building, earth in the system for the system to be isolated, then momentum of the system is conserved.

http://www.youtube.com/watch?v=QIxrXFHfGMc