- #1
ProPM
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I was looking at a picture (attachment) in a physics website and the following doubt arose:
I previously thought that the weight of the block (gravitational pull of the Earth on the block) caused a reaction force of the table, but now, from what I understand and, please correct me if I am wrong, those are not Newton's pair of forces because the weight is a force exerted by the Earth ON the block and the reaction force of the table is also ON the block, thus, two forces acting on the same body.
But, the diagram shows a second pair of forces it calls the normal reaction force due to the contact: I am not sure, but I remember my teacher saying that the nature of the normal reaction force is that as the block stands on the table it pushes some molecules of the table down and the molecules in turn push up. I am confused with that, because, if that really happened, wouldn't it be due to the weight and then the same problem of two forces acting on the body occur? So is that the nature of what the picture calls the normal reaction force due to contact?
Any help appreciated,
Thanks in advance,
ProPM.
I previously thought that the weight of the block (gravitational pull of the Earth on the block) caused a reaction force of the table, but now, from what I understand and, please correct me if I am wrong, those are not Newton's pair of forces because the weight is a force exerted by the Earth ON the block and the reaction force of the table is also ON the block, thus, two forces acting on the same body.
But, the diagram shows a second pair of forces it calls the normal reaction force due to the contact: I am not sure, but I remember my teacher saying that the nature of the normal reaction force is that as the block stands on the table it pushes some molecules of the table down and the molecules in turn push up. I am confused with that, because, if that really happened, wouldn't it be due to the weight and then the same problem of two forces acting on the body occur? So is that the nature of what the picture calls the normal reaction force due to contact?
Any help appreciated,
Thanks in advance,
ProPM.