0-60 mph Estimator (Educational)

Inspectable records

Ledger state

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

Area

Everyday & Life

Tranche

tranche-4

Evidence ID

t4-151

Ledger rows

1

No ledger note is attached.

Review findings

The base arithmetic is correct only conditionally: time_s = k × sqrt(weight_lb / hp). Final approval requires the exact published calibration constant and citation, the calibration range and error metrics, and an explicit drivetrain adjustment formula. The supplied k = 1.25 and neutral factor = 1.0 in the vectors are illustrative test parameters, not validated production values.

Formula and scope findings

• The stated formula is a plausible empirical correlation, but there is no universal standard value for k; the calibration constant, reference dataset, fitted domain, and source citation are missing.
• The input includes drivetrain type and promises an adjustment factor, but the formula does not define any drivetrain adjustment factor or how it modifies time_s.
• The formula is only conditionally valid within the calibration range; extrapolation to unusual vehicle weights or horsepower values is not justified.
• The formula assumes horsepower is a comparable power rating across vehicles and does not specify whether engine, crank, or wheel horsepower is required.

Unit assumptions

• weight_lb must be vehicle weight expressed in avoirdupois pounds, not kilograms or mass in another unit.
• hp must be horsepower using the same horsepower definition as the calibration dataset; engine/crank horsepower and wheel horsepower are not interchangeable.
• k has units of seconds divided by the square root of lb/hp, so its numeric value is valid only with weight in pounds and power in horsepower.
• The test vectors use an illustrative k = 1.25 and a neutral drivetrain adjustment factor of 1.0 solely to demonstrate the arithmetic; the spec must provide and cite the actual calibrated value.
• The output time_s is in seconds.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The specification does not provide the empirical calibration constant k or any drivetrain adjustment factors, so ordinary valid inputs cannot produce a numeric estimate. It also does not state input validation behavior for zero or nonpositive horsepower, zero weight, or unit ambiguity; zero horsepower causes division by zero and must be rejected.

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": {
    "weight_lb": 3000,
    "horsepower": 200,
    "drivetrain_type": "neutral_example",
    "drivetrain_adjustment_factor": 1,
    "k": 1.25
  },
  "expected_outputs": {
    "time_s": 4.841229
  },
  "working": "weight_lb / hp = 3000 / 200 = 15. sqrt(15) = 3.872983. drivetrain adjustment = 1.0, so 3.872983 × 1.0 = 3.872983. time_s = 1.25 × 3.872983 = 4.841229 s."
}

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