Acceleration due to gravity in London?

8.69 [m/s^2].

Sir Isaac Newton was the first to postulate gravity as we know it; a force exerted by anything with mass on anything else with mass, according to the product of the masses used and inversely...

At or near the surface of the earth, it's 9.8 meters (32.2 feet) per second2 . It's different at significant altitudes above the earth's surface, or on the surface of other, extraterrestrial bodies.

yes, this ADG helps the satellite to orbit earth. This is the centripital force

9.8 meters/seconds2or 32.3 feet/seconds2