Here is a question that I am having a hard time understanding. 75) the period of a hypothetical earth satellite orbiting at sea level would be 80 minutes. In terms of the earth's radius Re, the radius of a synchronous satellite orbit ( period 24 hours) is mostly: (A) 3 Re (B) 7 Re (C) 18 Re (D) 320 Re (E) 5800 Re the answer is (B) 7 Re, but how is that, and I was surprised that it takes the earth 24 hours to go around itself, but a satellite could make it in only 80 minutes :surprised . But most importantly is how did they get 7 Re for the answer, and I actually don't understand the question itself... Thank u so much!