Only One Metre
Suppose there exists a string that is wrapped snugly around the Earth at its equator. You add one metre to the string and hold it up at a point until all the slack is gone. Find the height between the point at which the string is being held up at and the ground directly below the string.
Assume the Earth is perfectly spherical and has a radius of 6400km
Assume that the string does not stretch
Answer in metres to one decimal place
Note that the question says that the string is being lifted at one point, not that it is being lifted evenly throughout the planet (basically, the string is not concentric to the equator after 1 metre is added.)