1. The problem statement, all variables and given/known data On each of the apollo missions the command module was placed in a very low aprox circular orbit above the moon. Assum the avrg hieght was 60km above surface of moon and moons radius is 7738km. (Mass of moon=7.34x10^22kg) What was the command modules orbital period? M=7.34x10^22kg r=7738+60 G=6.67x10^-11 2. Relevant equations t^2=4pi^2r^3/GM(source) 3. The attempt at a solution T^2=4pi^2(7738+60)^3 / (6.67x10^-11)(7.34x10^22) T^2= (1.87...x10^13) / (4.89...x10^12) T^2= 3.8237... T=Square Root(ANS) T= (1.9554.. Days x 24 Hours) = (46.93.. Hours) But the back of my worksheet says the answer is 17.2 hours or 6.18x10^4 seconds GAH I am so confused! >_< Your help is much appreciated!