Newton 3rd Law

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Francium87

Full Member
10+ Year Member
I have difficulties understanding newton third law when it comes to the following scenario:

when an object is sitting on the ground, would you say that its weight is the force generated by the object or generated by the gravity?

the reason why I am asking this because if the the force is generated by the object onto the ground then obviously the ground would reverse the same magnitude of force in the opposite direction..ok? however, the object is not moving up and the ground is not moving downward....so the only explanation of why the object is not moving is because the two forces acting on the object in the opposite direction making them cancel each other out (the downward force by the gravity vs the upward force by the ground.

Conclusion: the weight is the force generated by the gravity

Please if someone can confirm my thoughts or fill in anything I'm missing, would appreciated

Last edited:
W = mg

So yes, you can say it is generated by gravity.
But that force will be gone if the object was not there..

You just have to understand why W = Fn when it is on a horizontal surface..

W = mg

So yes, you can say it is generated by gravity.
But that force will be gone if the object was not there..

You just have to understand why W = Fn when it is on a horizontal surface..

Great! thanks