Re: [Phys-l] interaction

[Ian Sefton <I.Sefton@physics.usyd.edu.au>]

On 04/08/2007, at 12:59 PM, LaMontagne, Bob wrote:

> Nice example. Person A pulls on one end of the broomstick. The  
> boomstick exerts an equal and opposite force on Person A. This is  
> one pair of NTN 3 forces. Another pair is between Person B and the  
> other end of the broomstick. In this case no one would say that  
> Person A and Person B forms a NTN 3 pair (even though, as you  
> stated, they "interact" indirectly).

To re-inforce this point imagine that the broomstick (which has non- 
zero mass) is accelerating. Then the forces exerted by and on the two  
people are no longer equal in magnitude.


Cheers,
Ian