Local Gravitational Acceleration at Altitude

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Physics — Kinematics/Projectiles/Orbits, Forces/Energy/Momentum, Rotational Dynamics, Gravitation, Oscillations/Waves, Optics, E&M Fields, Relativity, Quantum, Statistical Thermo

Tranche

tranche-4

Evidence ID

t4-083

Ledger rows

1

No ledger note is attached.

Review findings

The acceleration formula is correct under the disclosed spherical, non-rotating idealization. Verdict is NEEDS_REVIEW because the requested '% vs surface g' output lacks an explicit formula and the radius convention for presets is unspecified.

Formula and scope findings

• g(h)=GM/(R+h)^2 is the standard spherical, non-rotating point-mass formula when M is the body's mass, R is its mean/reference radius, and h is radial altitude above that radius.
• The output '% vs surface g' has no formula specified. A standard interpretation is 100*g(h)/g(0)=100*(R/(R+h))^2, but this must be stated explicitly.
• The formula does not model planetary rotation, oblateness, local mass anomalies, or latitude-dependent surface gravity; the existing honest label correctly discloses the spherical, non-rotating idealization.

Unit assumptions

• Use G=6.67430e-11 m^3 kg^-1 s^-2.
• M must be in kilograms, R and h must be in metres, and the output g(h) is in m/s^2.
• Altitude h is radial height above the selected body's reference surface and must satisfy h>=0.
• For the test vectors, '% vs surface g' means 100*g(h)/g(0), where g(0)=GM/R^2.
• The planetary preset must define which radius is used, such as mean, equatorial, or volumetric radius; this choice affects the result.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The specification exposes a hard undefined-result trap at h=-R and a significant unit-convention hazard for an unlabeled altitude. A correct implementation must reject R+h=0 and require explicit altitude units; it must also reject negative altitudes if the stated above-surface domain is enforced.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "body": "Earth",
    "M_kg": 5.9722e+24,
    "R_m": 6371000,
    "altitude_m": 0,
    "G_m3_kg_s2": 6.6743e-11
  },
  "expected_outputs": {
    "g_m_s2": 9.820302,
    "percent_vs_surface": 100
  },
  "working": "GM=(6.67430e-11)(5.9722e24)=3.986025446e14 m^3/s^2. r=R+h=6.371000e6+0=6.371000e6 m. r^2=(6.371000e6)^2=4.0589641e13 m^2. g(h)=3.986025446e14/4.0589641e13=9.820302 m/s^2. g(0)=9.820302 m/s^2, so percent=100*(9.820302/9.820302)=100.0000%."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

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

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