How much force is required to hold the 100 ton tank to the earth when the earth spins and it is upside down?
I realize this is to you a "gotcha" question.
Upside down in relation to what?
You seem to think there is some force of gravity (though you deny gravity) "under" the earth that will pull things off of it.
Gravity is sufficient to keep your pen on your desk, and a tank on the ground.
Why are so many people willing to be "in" on the conspiracy with not a single one willing to break ranks with the evidence?
Why can you not see the northern stars from the south, and the southern stars from the north, but you can see both from the equator?
Why does perspective of the sun and moon show obital patterns rather than a pattern of circling overhead in a flat circuit over a flat earth?
Why can you not see features on the earth that are not visible over the horizon, but you can see them even being further away but at a higher elevation?
Why do airline travel times and routes reflect a globe earth and not a flat earth?
Why do star parallaxes show star distances to be well outside the limits imposed on a "flat earth"?
Why does the Bible speak in so many places of the sun "rising" and "setting" rather than "approaching" and "receding"?
Much love!