v= √( (G* Merde) / (6371+400)km )
= √( (6,67*10-11 m^3 kg-1 s-2 * 5,97*1024 kg) / (6371+400)km )
= √( (39,82 m^3 kg-1 s-2 *1013 kg) / 6771000m )
= √( (5,881*10-6 m^2 s-2 *1013)
= √( (5,881*10^7 m^2 s-2 )
= √( (58810000 m^2 s-2 )
= 7668 m/s = 7,668 km/s