Moving and newton's Third Law
I am having difficulty explaining Newton's Third Law of Motion in regard to every action force has an equal and opposite reaction force. in that case how does anything move?
F net = ma
and F1,2 = -F2,1
So let us say mass one is a person and mass two is Earth. To walk, you push against Earth just as hard as Earth pushes on you.
M earth (a) = -m person (A)
Wince these are equal and opposite products, the smaller mass will have the main acceleration.
---Nathan A. Unterman
A good conceptual physics source that is easy to read and will help you is:
Paul Hewitt "Conceptual Physics" Addison-Wesley
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Update: June 2012