Gravity is really Density!

The two types of 'gravity' are discussed; acceleration due to "gravity", g, in metres per second squared, and the universal "gravitation" constant, G, in newtons metre squared per kg squared
What role does air pressure and density play in this?
A few equations here, starting from first principles with assumptions, and the all important dimensional analysis of units!
G is compared with the Coulomb constant
Bernoulli Equation is briefly discussed
Screenshots of spreadsheet calculations are included, compared and contrasted
The "killer question" then is what is responsible for this acceleration?
https://commons.wikimedia.org/wiki/File:UGC_1810_and_UGC_1813_in_Arp_273_(captured_by_the_Hubble_Space_Telescope).jpg
NASA, ESA, and the Hubble Heritage Team (STScI/AURA), Public domain, via Wikimedia Commons
https://commons.wikimedia.org/wiki/File:Doctor_Zirkel_follows_Newton%27s_famous_steps_under_the_fabled_Wellcome_V0011942.jpg
See page for author, CC BY 4.0 https://creativecommons.org/licenses/by/4.0, via Wikimedia Commons
https://kg-m3.com/material/apple
https://en.wikipedia.org/wiki/Gravitational_constant https://en.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation
https://commons.wikimedia.org/wiki/File:Gravity_Big_G_Measurements_NIST.png
Stephan Schlamminger, Public domain, via Wikimedia Commons
https://en.wikipedia.org/wiki/Coulomb%27s_law
https://usapple.org/apple-varieties
http://hyperphysics.phy-astr.gsu.edu/hbase/pber.html
https://www.mide.com/air-pressure-at-altitude-calculator
https://en.wikipedia.org/wiki/Standard_gravity https://en.wikipedia.org/wiki/Density_of_air
https://www.engineersedge.com/materials/densities_of_metals_and_elements_table_13976.htm
https://en.wikipedia.org/wiki/Water https://en.wikipedia.org/wiki/Standard_sea-level_conditions
https://commons.wikimedia.org/wiki/File:Zinkanode_neu.jpg Elvaube This file was uploaded with Commonist. This photograph was taken with a Nikon D70, CC BY-SA 3.0 DE https://creativecommons.org/licenses/by-sa/3.0/de/deed.en, via Wikimedia Commons