[填空题]
A person on a rocket traveling at 0.50c (wi2ywr;j0o u *n1y8oqlkth respect to 8w9 rwyel0y4u aes0+bthe Earth) observes a meteor come from behind and pass her at a speed she measures as 0.50c. How b 0y+w9esau 8yl4we0r fast is the meteor moving with respect to the Earth? u = c
