Why Do Objects Move Despite Equal and Opposite Reactions?

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
4 replies · 3K views
Dirtyhand
Messages
1
Reaction score
0
It says that every reaction there is a opposite and equal reaction. Why do things still move if everything is opposite and equal?
 
Physics news on Phys.org
Basically, objects are independent of each other, i think you are thinking of them as a system
Example: I push on a BOX. The box pushes back on ME. Something else does not push from the opposite side of the box to balance my push. The box experiences an unbalanced force and possibly accelerates.
 
to put it a different way, the forces act on different objects.
think of you swimming... you kick back your legs against the water, applying force on it by pushing it backwards, but by Newtons third law, the water will push back on you. The end result being that you get pushed forward by the water, and hence, move forward, and the water gets pushed back by your feet...
 
Dirtyhand said:
It says that every reaction there is a opposite and equal reaction. Why do things still move if everything is opposite and equal?

Don't confuse Newton's third law with the second.

http://en.wikipedia.org/wiki/Newton's_laws_of_motion
 
Dirtyhand said:
It says that every reaction there is a opposite and equal reaction. Why do things still move if everything is opposite and equal?

The forces are applied to different bodies.
 
Last edited: