Question

fan & medal

A stack of books is sitting on a table.

Which force is pulling downward on it?
buoyant force
pressure force
gravitational force

Answer 1

Regardless the position of a body in any surface around our planet, the force of gravity always acts on it. The reason why we rest 'downwards'. Even in the moon, though the gravity be so low it still pulls us downwards. So for the case of books, the force of gravity acts the greatest. You could believe that otherwise, the books would be floating in air.

Answer 2

I think that a stack of books exerts on the table a pressure force, and by the third principle of Newton the table exerts a force opposite to that pressure in order to sustain the stack of books:

Answer 3

@kneaux