Does a resting object exert its weight as force on a surface?

[Krishna24]

I have read on the internet that if an object rests on a table, that object will exert the force of its weight on the table. But, for some reason, that doesn't make sense to me. If I have a 10 kg book that rests on a table, the gravitational force on that object will be 98 N. If gravity is exerting a force on the book, why would the book be exerting a force of 98 N on the table?

 

[phinds]

I have read on the internet that if an object rests on a table, that object will exert the force of its weight on the table. But, for some reason, that doesn't make sense to me. If I have a 10 kg book that rests on a table, the gravitational force on that object will be 98 N. If gravity is exerting a force on the book, why would the book be exerting a force of 98 N on the table?

What do you think is holding the book up? Why does it not just fall to the center of the Earth?

 

[jack action]

If you put your hand on the book and push with a force of 100 N, you exert a force on the book, just like gravity does. What is the force «felt» by the table now? It would be 198 N, i.e the combination of the forces exerted by both you and gravity.

From the point of view of the table, it is the book that pushes on it. The table doesn't «see» the hand or the gravity pushing on the book.

 

[jtbell]

why would the book be exerting a [downwards] force of 98 N on the table?

Because (a) the table is exerting an upwards force of 98N on the book, and (b) Newton's Third Law.

 

[A Lazy Shisno]

When you put something really, really heavy on a table, the table bends until it snaps. That's because the object, which is trying to get to the ground, is exerting a force on the table. It's the same as if the object is placed on the ground; it's still trying to go downwards and so it is exerting a force on the ground, and the ground is exerting an equal and opposite force on it, keeping it from just falling through the ground.

 

[Krishna24]

When you put something really, really heavy on a table, the table bends until it snaps. That's because the object, which is trying to get to the ground, is exerting a force on the table. It's the same as if the object is placed on the ground; it's still trying to go downwards and so it is exerting a force on the ground, and the ground is exerting an equal and opposite force on it, keeping it from just falling through the ground.

When you put something really, really heavy on a table, the table bends until it snaps. That's because the object, which is trying to get to the ground, is exerting a force on the table. It's the same as if the object is placed on the ground; it's still trying to go downwards and so it is exerting a force on the ground, and the ground is exerting an equal and opposite force on it, keeping it from just falling through the ground.

Thank you so much. I understand it now.

 

[Krishna24]

Because (a) the table is exerting an upwards force of 98N on the book, and (b) Newton's Third Law.

Thank you very much for you reply. I understand it now