A drone is stationary at a spatial point about 1 m from the Great Wall, which is a vertical plane rectangle with height 5 m and infinite length. The altitude of the drone is a random number between 0 m and 5 m. The drone may be pointing in any direction (which may even be tilted upwards or downwards), however it does not know which. It can travel in any direction, and switch directions accurately. It gets to know when it touches the ground plane, and can then determine its own tilt upwards/downwards by travelling a small distance on the ground (about zero).
Q 1: What is the minimum distance that must be travelled to ensure it hits the Great Wall?
Q 2: If the objective is to minimise displacement between initial and final positions, what upper value can it be guaranteed to outperform?