Source: https://guthlabs.ai/docs/instruments/power-calculator/mechanism/

instrument mechanism / verified-clean

# Power Calculator mechanism

The inspectable method record for Power Calculator, kept separate from implementation and qualification.

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

## Model scope

The arithmetic is valid under the stated SI-unit assumptions and with parallel force and velocity. The catalog claim needs clarification that W/t is average power, that Fv is a special case of F·v, and that the horsepower toggle means mechanical horsepower using 746 W/hp.

- P = W/t is average power over the interval, not necessarily instantaneous power.

- The general force-velocity formula is P = F·v = Fv cos(theta); P = Fv is correct only when force and velocity are parallel and in consistent SI units.

- The symbol W is ambiguous because it can denote work in joules or the watt unit of power.

- The specification does not define whether horsepower conversion is mechanical horsepower (746 W/hp) or metric horsepower (approximately 735.5 W/hp).

## Units and conventions

- Work W is measured in joules (J) and time t in seconds (s), producing power in watts (W).

- Force F is measured in newtons (N) and velocity v in metres per second (m/s), producing power in watts (W).

- The horsepower toggle is assumed to use mechanical horsepower: 1 hp = 746 W, so hp = P_W/746.

- For nonparallel force and velocity, an angle theta and the dot-product relation Fv cos(theta) are required.

- Time must be converted to seconds and work to joules before applying P = W/t.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "mode": "work_time",
    "W": 1200,
    "W_unit": "J",
    "t": 30,
    "t_unit": "s"
  },
  "expected_outputs": {
    "P_W": 40,
    "P_hp": 0.0536193029
  },
  "working": "P = W/t = 1200 J / 30 s = 40 J/s = 40 W.\\nP_hp = 40 W / 746 W per hp = 0.0536193029 hp."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

The specification exposes an undefined zero-time input and does not define behavior when both input representations are supplied or whether force-velocity power is signed or magnitude-only. The calculator should reject t=0 and require an explicit mode and sign convention.

## Other records

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