The Earth's orbit has a mean radius of 1.5 ˛ 108 km. Over a six-month period, the apparent position of a particular star varies by 0.00014e due to parallax. How distant is the star, in ly? (1 ly = 9.46 ˛ 1015 m)

Einstein's principle of equivalence:  No experiment can be performed that could distinguish between a uniform gravitational field and an equivalent uniform acceleration. or Gravitational mass is equivalent to inertial mass.