How far above the earth's surface will the acceleration of gravity be half what it is at the surface?

The earth's gravitational pull would be halved when the distance above the earth would equal the radius of the earth. In this case, from the Earth's crust to the core is 1,64. If we want to half the gravitational pull on the Earth, we must consider the equation for gravitational acceleration: g = GM/r^2. G is the gravitational constant of the Earth, and the mass of the Earth. r is the radius of the earth. If g is to be halved, r^2 must be doubled. Therefore, one can use the square root of 2 to multiply the left side of the original equation. If the distance from the Earth's surface to its core is originally 6,378 km, we multiply it by .141414 (square root of 2) to come to 9,020 km. Subtract the original radius, and one comes to 2,642km. So 2,642 km above the Earth, the gravitational acceleration is halved of what it is on the surface.

Neptune is the eighth planet from the sun. it was the first planet to get its existence predicted by  mathematical calculations  before it was actually seen through a telescope on sept. 23, 1846. irregularities in the orbit of  uranus  led french astronomer alexis bouvard to suggest that the gravitational pull from another celestial body might be responsible. german astronomer johann galle then relied on subsequent calculations to   spot neptune via telescope. previously, astronomer galileo galilei sketched the planet, but he mistook it for a star due to its slow motion. in accordance with all the other planets seen in the sky, this new world was given a name from greek and roman mythology — neptune, the roman god of the sea.