Physics
posted by tom .
A satellite of mass 210 kg is launched from a site on Earth's equator into an orbit at 210 km above the surface of Earth.
(a) Assuming a circular orbit, what is the orbital period of this satellite?
(b) What is the satellite's speed in its orbit?
(c) What is the minimum energy necessary to place the satellite in orbit, assuming no air friction?
J

For (a) and (b), the satellite mass will not matter. The orbit distance from the center of the earth is R = 6378 + 210 = 6588 km. Speed is
V = 2 pi R/P
where P is the period.
Get the period from
G M/R^2 = V^2/R
G M = V^2*R = 4 pi^2 R^3/P^2
Solve for P
M is the earth's mass
Energy required = (1/2) m V^2 + GMm[1/Re  (1/(Re + 211,000m)]
m is the satellite mass
There is a small additional term (+ or  that takes into account the rotational speed of the earth at the launch point. That gives the rocket launcher a bit of a boost, especially at the equator. 
I need a better explanation than that, and an answer to show you are right. thanks
Respond to this Question
Similar Questions

Physics
A satellite of mass 220 kg is launched from a site on Earth's equator into an orbit at 200 km above the surface of Earth. (a) Assuming a circular orbit, what is the orbital period of this satellite? 
physics
Two Earth satellites, A and B, each of mass m, are to be launched into circular orbits about Earth's center. Satellite A is to orbit at an altitude of 7460 km. Satellite B is to orbit at an altitude of 20500 km. The radius of Earth … 
physics
Two Earth satellites, A and B, each of mass m, are to be launched into circular orbits about Earth's center. Satellite A is to orbit at an altitude of 7460 km. Satellite B is to orbit at an altitude of 20500 km. The radius of Earth … 
PHYSIC
1)What must be the orbital speed of a satellite in a circular orbit 740 above the surface of the earth? 
Physics help PLZ!!
Estimate the energy required from fuel to launch a 1465 kg satellite into orbit 1375 km above the Earth’s surface. Consider two cases: (a) the satellite is launched into an equatorial orbit from a point on the Earth’s equator, … 
physics
Estimate the energy required from fuel to launch a 1465 kg satellite into orbit 1375 km above the Earth’s surface. Consider two cases: (a) the satellite is launched into an equatorial orbit from a point on the Earth’s equator, … 
physics
A spy satellite was launched into a circular orbit with a height of 599 km above the surface of the Earth. Determine its orbital speed and period. (The mass of the Earth is 5.97 1024 kg, and the radius of the Earth is 6370 km.) 
Physics
Some communication satellites are put into a circular geosynchronous orbit in which the satellite remains above a certain position on the earth's equator as it orbits. Such a satellite would always be in the same position in the sky … 
physics
A satellite of mass 225 kg is launched from a site on Earth's equator into an orbit at 200 km above the surface of Earth. (The mass of the Earth is 5.98 1024 kg, and the radius of the Earth is 6.38 103 km.) (a) Assuming a circular … 
physics
A satellite of mass 205 kg is launched from a site on Earth's equator into an orbit at 200 km above the surface of Earth. (a) Assuming a circular orbit, what is the orbital period of this satellite?