Learning Newton's Second Law from the Garden Hose

My son was watering our little patch of vegetables this weekend, when he suddenly fell down on his backside.  He jumped up and said, "Hey!  The hose knocked me over."  I am suspicious that he may have been dramatizing a little bit.  However, it was fun to talk about.

Not only was the water being forced out of the hose, it was putting a force back on the hose.  For every force there is an equal force in the opposite direction.