Question on circular motion and Newton's laws

[excel000]

1. What are the action/reaction forces when twirling a rubber stopper attached to a string? How does circular motion illustrate Newton's first law?



2. F=ma



3. I thought about centripetal and centrifugal, but my teacher said centrifugal force isn't a real force.

 

[PhanthomJay]

Your teacher of course is correct. When you talk of 'action/reaction' forces, you're talking usually about Newton's 3rd Law 'force pairs', whereby if A exerts a force on B, then B exerts a force on A that is equal in magnitude but opposite in direction to it. Does that help?

 

[excel000]

yea, but i can only think of the tension force, i can't think of the opposite to that. how about the force applied by the hand and the tension force?

 

[PhanthomJay]

yea, but i can only think of the tension force, i can't think of the opposite to that. how about the force applied by the hand and the tension force?

Yes, that's one of them. If the hand pulls on the string creating a force in the string, then what can you say about the force of the string on the hand? What about the stopper/string force pair?