Source: https://guthlabs.ai/docs/instruments/gravitational-potential-energy-calculator/mechanism/

instrument mechanism / verified-clean

# Gravitational Potential Energy Calculator mechanism

The inspectable method record for Gravitational Potential Energy Calculator, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## 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

[01**Overview**](<https://guthlabs.ai/docs/instruments/gravitational-potential-energy-calculator/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/gravitational-potential-energy-calculator/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/gravitational-potential-energy-calculator/qualification/>)

## 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`