@thi.ng/units/constants/velocities.js

Extensible SI unit creation, conversions, quantities & calculations (incl. ~170 predefined units & constants)

import { quantity } from "../unit.js";
import { m_s } from "../units/velocity.js";
const SPEED_OF_LIGHT = quantity(299792458, m_s);
const SPEED_OF_SOUND_IN_AIR = quantity(343.14, m_s);
const SPEED_OF_SOUND_IN_WATER = quantity(1482, m_s);
export {
  SPEED_OF_LIGHT,
  SPEED_OF_SOUND_IN_AIR,
  SPEED_OF_SOUND_IN_WATER
};