pound per cubic foot

{
  "id": "NISTu204",
  "unitsml_id": "u:pound_per_cubic_foot",
  "name": "pound per cubic foot",
  "names": [
    {
      "value": "pound per cubic foot",
      "lang": "en"
    }
  ],
  "symbols": {
    "unicode": "lb/ft³",
    "ascii": "lb*ft^-3",
    "html": "lb/ft<sup>3</sup>",
    "latex": "\\ensuremath{\\mathrm{lb/ft^3}}",
    "id": "lb*ft^-3",
    "mathml": "<mrow><mi mathvariant='normal'>lb</mi><mo>/</mo><msup><mrow><mi mathvariant='normal'>ft</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow>"
  },
  "identifiers": [
    {
      "type": "nist",
      "id": "NISTu204"
    },
    {
      "type": "unitsml",
      "id": "u:pound_per_cubic_foot"
    }
  ],
  "references": [
    {
      "type": "informative",
      "authority": "qudt",
      "uri": "http://qudt.org/vocab/unit/LB-PER-FT3"
    }
  ],
  "short": "pound_per_cubic_foot",
  "root": false,
  "composite": true,
  "quantities": [
    {
      "id": "NISTq51",
      "name": "density",
      "type": "derived"
    }
  ],
  "dimension": {
    "id": "NISTd30",
    "name": "mass density",
    "expression": "L-3·M",
    "components": [
      {
        "key": "length",
        "symbol": "L",
        "power": -3
      },
      {
        "key": "mass",
        "symbol": "M",
        "power": 1
      }
    ],
    "dimensionless": false
  },
  "scale": {
    "id": "continuous_ratio",
    "name": "continuous ratio scale"
  },
  "systems": [
    {
      "id": "non-SI_not_acceptable",
      "name": "non-SI and not acceptable",
      "short": "nonsi-unacceptable",
      "acceptable": false
    }
  ],
  "root_units": [
    {
      "power": 1,
      "unit": {
        "id": "NISTu201",
        "name": "pound (avoirdupois)",
        "symbol": "lb"
      },
      "prefix": null
    },
    {
      "power": -3,
      "unit": {
        "id": "NISTu78",
        "name": "foot",
        "symbol": "′"
      },
      "prefix": null
    }
  ]
}