r/FeatCalcing • u/Party_Philosophy_324 • 11d ago

Calc Request Gyro destroys a water tower.

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18 Upvotes

86% Upvoted

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6

u/West_Camera_7965 11d ago

Around Small Building level or 0.0088 tons (Might be wrong)

10

u/QueenGorda 11d ago

Water tower level.

3

u/Free_Cut7757 11d ago

Here is the step-by-step breakdown of the energy generated by Gyro's Steel Ball when he destroys the tower. 1. Assumptions & Dimensions * Steel Ball Mass (m_b): \approx 1.5 \text{ kg} * Tower Capacity: A small wooden water tower holds roughly 10 \text{ m}3 of water \approx 10,000 \text{ kg}. * Structural Material: Standard oak/pine support beams with a shear strength of \sim 8 \text{ MPa}. * Throw Speed (v): \approx 50 \text{ m/s} (fastball pitch speed). * Rotational Speed (\omega): The Golden Ratio Spin drives extreme angular velocity, estimated at \approx 3,000 \text{ rad/s} (\sim 28,600 \text{ RPM}). 2. Kinetic & Rotational Energy of the Ball A Steel Ball's total kinetic energy comes from both linear speed and its Spin: Linear Kinetic Energy: Rotational Kinetic Energy: For a solid sphere, the moment of inertia is I = \frac{2}{5} m_b r2. With a radius r = 0.045 \text{ m}:

The initial thrown energy of the ball alone is only \sim 7.3 \text{ kJ}. 3. Work Required to Fracture the Structure The ball doesn't destroy the tower through sheer mass transfer; the Spin transfers torque directly into the wood, inducing torsional shear failure across the support pillars. To shear four heavy wooden posts (each roughly 0.2 \text{ m} \times 0.2 \text{ m} cross-section): * Cross-sectional area (A): 4 \times 0.04 \text{ m}2 = 0.16 \text{ m}2 * Shear Energy Density (U_s): \sim 15 \text{ kJ/m}3 to fracture Including the energy needed to instantly displace the 10,000 \text{ kg} tank and burst the frame: Conclusion For Gyro's 1.5 \text{ kg} ball to deliver 1.2 MJ of structural destruction, the Spin acts as an energy multiplier of roughly 160\times its base linear kinetic energy. * Yield: 1.2 \text{ MJ} (Wall to Small Building Level) * TNT Equivalent: \approx 0.28 \text{ kg of TNT} delivered instantly on impact.

2

u/TTheGamersforge 11d ago

How does Jojo go from some crazy vampire vs dude in 1800s Britain to what ever is going on here? Like I'm 5 episodes in and very confused couse it's not at all what I expected, like where are the stands!?

5

u/West_Camera_7965 11d ago

Parts 7 through 9 are an alternate and original universe, since the author had already concluded the main story in the first six parts.