# Universal Gravitation - Satellites

The Explorer VIII satellite, placed into orbit November 3, 1960, to investigate the ionosphere, had the following orbit parameters: perigee, 459 km; apogee, 2289 km (both distances above the Earth's surface); period, 112.7 min. Find the ratio vp/va of the speed at perigee to that at apogee.

Well in order to know the answer you first gotta know what kind of orbit this satellite makes. In this case it is quite straightforward to conclude we are dealing with an elliptical orbit. Now, i don't know at what level you are dealing with these issues here but i am sure you have some formula's in your notes that relate the elliptical caracteristics to the dynamics of the movement. Something like the speed of the object along the ellips as a function of the great axis a...or the eccentricity of the trajectory...

regards
marlon

Pyrrhus
Homework Helper
He could use conservation of angular momentum for the satellites.

Cyclovenom said:
He could use conservation of angular momentum for the satellites.

true story...it is this property together with conservation of total energy that will give rise to the formula's needed to solve this problem...

marlon