套公式GMm/R^2 = mv^2/R = mw^2R = mR/T^2化简得常数GM = R^3/T^2地球半径取4000英里。于是有(240000+4000)^3/28^2 = (x+4000)^3/1^2解得x≈22460 miles好好学习天天向上
