Hi guys,(adsbygoogle = window.adsbygoogle || []).push({});

i cant seem to find the answer .

A satellite in earth orbit has a perigee velocity of 8 km=s and period of 2 hours. From this information,

determine all the orbit parameters that you can. From those parameters, determine its altitude at perigee

--------------------------------------------------------

my vp=8km/sec

T=7200sec

Vp=sqrt(GM/r)---is this right and is r =rp?

how do i calculate my semi major axis? is it from kepler's 3rd law? im stuck at finding rp and eccenctricity and ive been going at this for hours without proper examples in books/online.

Someone please help!

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Orbit Dynamics

**Physics Forums | Science Articles, Homework Help, Discussion**