Physics · Ch 1 — Rotational Dynamics
Well (or Wall) of Death (मौत का कुआँ)
Well (or Wall) of Death (मौत का कुआँ)
A dramatic application of the same idea is the 'well of death' (or 'wall of death') stunt: a vertical, hollow cylindrical wall of radius r, inside which a vehicle is driven in horizontal circles, its wheels pressed against the vertical wall by the circular motion itself. Three forces act on the vehicle (treated as a point): the normal reaction N from the wall, acting HORIZONTALLY, directed inward towards the central axis of the cylinder; the weight mg, vertically downward; and the force of static friction between the wall and the tyres, acting VERTICALLY UPWARD along the wall surface. This friction is static because it must prevent the vehicle sliding DOWN the vertical wall under gravity.
Drawn by us to help you understand the concept clearly, and verified to make sure it's accurate. For exams, practice from your textbook's own diagram.
What this figure shows. A vertical cross-section of a vertical cylindrical wall of radius r, with a vehicle (treated as a point) shown against the inside of the wall, driven in a horizontal circle. Three force arrows act on the vehicle: normal reaction N drawn horizontally, pointing INWARD from the wall towards the central vertical axis of the cylinder (this is the resultant centripetal force); weight mg drawn vertically downward; and the force of static friction drawn vertically UPWARD along the wall surface, exactly cancelling mg since it is the only upward force present (there is no normal-reac …
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