External force is a myth…

Sounds funny???

Here is why …

Firstly, when we say “External…”, we need to realise that we refer to what is external with respect to the system that we consider to be under study. If we consider the system below,

spheres.jpg

and call the sphere on the top right as the system, then the reaction force that it perceives from the other sphere and the wall are external forces to it. But if we consider the whole thing  as a system, then there is no external force.

Wait. What if I add gravity? Then that becomes an external force. Right? Yes. If you limit ur system definition to the sphere and the walls. If you include the earth which creates the gravity as part of the system, then that too remains an internal force…

lets go further… Force itself is a myth….

Come on.. Thats taking it too far.. Forces do exist.. I apply a force and push that rock  off the cliff.. Right????

push.jpg

No.  What you do is to supply energy to the rock. How you do this is by transfering momentum from you to the rock. The rock gains energy, displaces and falls off… To make things convenient for ourselves, we introduce a concept called the force. We say that we applied a force on the rock. And the rock reacted back with an equal and opposite force. And that two forces existed. Its something like telling one lie to cover up for the lie we told earlier. Its just an anology. Not meant to offend anyone.

What else supports the fact that “force is a myth”. OK. How do we measure force? Its always indirect. Force gauges actually measure displacement caused by that force onto some plate or whatever. They have a calibration which says this much displacement must mean that this much force was applied. Then they report this.  Note: No one ever saw the force. What we saw is only the displacement.

Do we not feel the force when someone pushes us??? No. We feel the acceleration that we gain due to the energy / momentum that was transfered to us. mass times acceleration is called force and so we could say that we felt a force. But strictly speaking, we felt only the acceleration…

Hence proved…..   Do u agree?? Write in ur comments…

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