Why can't you not detect the force of the attraction between or foot and the leg of your chair?

Answer 1

because it is negligible, in other words it is too small for our body's to sense

The formula to find the force between 2 objects is F = G x(m1 m2)/r^2
where G is a constant of 6.67 x 10^-11

r being the distance between the 2 objects
and m1 and m2 being mass of both objects respectively.
as G is a very very small number one or both objects have to be of considerably large mass in order to feel any force between them, in your case since leg of your chair and you and small masses, the force would be less than than enough to be felt.

Answer 2

Yes but in terms of what gravity, magnetic, electrostatic force of attraction ?

By gravity use newtons law

=F=G.M.M/r^2

By magnetic and electrostatic use columbs law of attaraction

1/4pie £o* e^2/r^2

Answer 3

There is a gravitational attraction, but neither your foot nor your chair have much mass, so the effect is minuscule. We're accustomed to resisting much greater forces, like the attractive force of gravity between your foot and the far more massive Earth; so we don't notice the tiny, TINY force between your foot and the chair.

Also, the attractive force between your foot and the chair behind you is counteracted by the attractive force between your foot and the table in front of you, so even in zero gravity, the net effect would be nil.