import numpy as np

# conversions
class CV:
  # Speed
  MPH_TO_KPH = 1.609344
  KPH_TO_MPH = 1. / MPH_TO_KPH
  MS_TO_KPH = 3.6
  KPH_TO_MS = 1. / MS_TO_KPH
  MS_TO_MPH = MS_TO_KPH * KPH_TO_MPH
  MPH_TO_MS = MPH_TO_KPH * KPH_TO_MS
  MS_TO_KNOTS = 1.9438
  KNOTS_TO_MS = 1. / MS_TO_KNOTS

  # Angle
  DEG_TO_RAD = np.pi / 180.
  RAD_TO_DEG = 1. / DEG_TO_RAD

  # Mass
  LB_TO_KG = 0.453592


ACCELERATION_DUE_TO_GRAVITY = 9.81  # m/s^2