Gravitational Potential Energy Calculator mechanism

Model scope

NEEDS_REVIEW because the exact ambiguity is whether the local output is intended to be absolute U or ΔU, and because g, SI-unit requirements, the mode selector, and the reference level for h are unspecified. The honest label is currently n/a; the instrument should disclose the zero-at-infinity convention for the general formula and the reference level and g value for near-surface mode.

• U=−Gm1m2/r is correct for two point masses, or spherically symmetric bodies outside their mass distributions, with zero potential at infinite separation; r must be center-to-center distance.
• U=mgh is the near-surface change in potential energy (ΔU), not an absolute gravitational potential energy unless h is explicitly measured from a declared zero reference.
• The local formula requires a specified gravitational acceleration g; the spec lists masses and h but does not identify g as an input or declare a default value.
• The general and local calculation modes are not explicitly represented in the input contract, creating ambiguity about which formula and required fields apply.

Units and conventions

• Use SI units: kilograms for mass, meters for r and h, meters per second squared for g, joules for U.
• Use G=6.67430×10^-11 N·m²/kg² unless the instrument exposes G as an input or clearly documents this constant.
• For near-surface calculations, use g=9.80665 m/s² by default only if that default is explicitly documented; h is signed displacement from the chosen reference level.
• In the general formula, r is center-to-center separation and must be strictly positive.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "mode": "general",
    "m1_kg": 5.972e+24,
    "m2_kg": 1000,
    "r_m": 7000000,
    "G_N_m2_per_kg2": 6.6743e-11
  },
  "expected_outputs": {
    "U_J": -56941313714.2857
  },
  "working": "U=−Gm1m2/r\n=−(6.67430×10^-11)(5.972×10^24)(1000)/(7.000×10^6)\n=−(6.67430×5.972)×10^16/(7.000×10^6)\n=−39.8589196×10^16/(7.000×10^6)\n=−5.69413137142857×10^10 J\n=−56,941,313,714.2857 J"
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The general formula has an undefined division-by-zero input at r=0 and must reject it rather than return a numeric result. A separate hazard is that general and near-surface outputs use different reference conventions, so switching modes can produce apparently inconsistent values unless the reference level is made explicit.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json