Rolling Without Slipping Solver

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-6

Evidence ID

t6-037

Ledger rows

1

No ledger note is attached.

Review findings

The acceleration algorithm is a direct lookup-table evaluation, not an iterative method. The core acceleration formula is standard, but the instrument needs explicit angle units, an unambiguous cylinder definition, and additional inputs/formulas for velocity and race results. The honest-label warning about idealized no-slip and no rolling resistance is appropriate but should also state that sufficient static friction is assumed.

Formula and scope findings

• The acceleration formula a=g sin(theta)/(1+I/(mR^2)) is correct for a rigid body rolling down a straight incline without slipping, assuming gravity is uniform and the object starts with no dependence on translational initial velocity.
• The stated solid-sphere example is correct: I/(mR^2)=2/5, so a=g sin(theta)/(1+2/5)=(5/7)g sin(theta).
• Velocity is claimed as an output, but no ramp length, elapsed time, initial velocity, or velocity formula is specified. For release from rest over distance s, the required formula is v=sqrt(2as); after time t, v=at.
• The shape lookup is ambiguous for cylinder: a solid cylinder or disk has I/(mR^2)=1/2, while a hollow cylinder has a different ratio. The catalog must explicitly define which cylinder is intended.
• The no-slip condition is not merely a label: static friction must be sufficient. For a body with k=I/(mR^2), the required condition is mu_s >= k tan(theta)/(1+k).

Unit assumptions

• Use g=9.80665 m/s^2 unless a configurable value is explicitly provided.
• Angles are interpreted as degrees in these vectors and converted before applying sine: theta_rad=theta_deg*pi/180. The specification does not state whether the UI accepts degrees or radians.
• I/(mR^2) is dimensionless; acceleration is reported in m/s^2.
• For velocity checks, ramp length is in meters, initial velocity is in m/s, and the object is released from rest unless otherwise stated.
• The tested cylinder is explicitly treated as a solid cylinder, equivalent to a solid disk, with I/(mR^2)=1/2.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The specification defines only four recognized shapes and gives no behavior for an unrecognized shape. Without explicit validation, an unknown shape produces an undefined inertia-ratio lookup and therefore an undefined acceleration; the solver must reject it.

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": {
    "shape": "solid sphere",
    "angle": 30,
    "angle_unit": "degrees",
    "g": 9.80665
  },
  "expected_outputs": {
    "acceleration_m_per_s2": 3.502375
  },
  "working": "k=I/(mR^2)=2/5=0.4. Convert angle: sin(30 degrees)=0.5. Denominator=1+0.4=1.4. Numerator=g sin(theta)=9.80665*0.5=4.903325. Therefore a=4.903325/1.4=3.502375 m/s^2."
}

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-tranche6/tranche6-results.json
• BOUNDARY_HAZARD_CATALOG.json