Comments on Why we can't find a particle accelerating unless there's some other particle accelerating somewhere else?
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Why we can't find a particle accelerating unless there's some other particle accelerating somewhere else?
I was reading "Introduction to classical Mechanics" by David Morin. In that book they wrote that
The third law says we will never find a particle accelerating unless there’s some other particle accelerating somewhere else. The other particle might be far away, as with the earth–sun system, but it’s always out there somewhere.
But, when we are walking, running. We are accelerating. Even, vehicles are accelerating also. But, why the definition says,"we can't find a particle accelerating ......." Seems like they talking about QM (I am not sure) cause, in "Classical" World I can see everything accelerating but, they had talked about particle which means they are referring to Quantum World. It's looking like Quantum Entanglement cause, when a particle (big object) is far away than, they can't contact in Classical World but, if we think of QM than, they can contact (That's why I am referring to QM).
$$\frac{d_{Ptotal}}{dt} = \frac{dp_1}{dt} + \frac{dp_2}{dt}$$
They wrote the above equation. Then talked about above definition. What I understood from the equation that is,"We can't find a particle accelerating cause, a particle always (not in Quantum World) has equal of negative force so, until two particles contact each other their momentum is forever $0$"
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But, when we are walking, running. We are accelerating.
Wrong.When you are walking you're moving at a costant speed.
The third law says we will never find a particle accelerating unless there’s some other particle accelerating somewhere else
The book says that because of Netwon's 3rd law which says that forces only come in pairs , for each action there is a reaction.
If two marbles collide then during the contact a force will be exerted on each marble , the one being the reaction of the second force.But those account as internal forces so the total change in momentum of the system is 0.
Hope this helps.
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