David W. answered 06/08/18
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We usually use a Coordinate System to locate position and to measure distance (change in position) and to measure speed (change in position per unit of time) and to measure acceleration (change in speed per unit of time).
"stable in a position at a height for one hour," means that the done maintains that same position (relative to the spot on the Earth below it) for the hour. No change in position -- zero speed -- zero acceleration. If you were standing in the spot on the surface of the Earth below the drone, the drone would appear not to move.
However, the Earth rotates once per day. The drone would move around the Earth at the same angular speed as the Earth rotates. Experiment: stick your chewing gum to a ball and roll the ball; the gum moves even though it keeps its same position on the ball.
Not only that, the Earth revolves around our Sun. That means the Earth spins roughly 365 times as it makes one loop (one year) around the Sun, [note: Earth is 93 million miles from our Sun, so that's a lot of movement even though the drone would still be over the same spot on the Earth].
Oh, yes, and our Sun is moving very fast. We don't have a fixed reference point to use as an Origin for measuring that, so we don't know how fast. However, scientists have determined that the universe of celestial bodies is rapidly expanding.