1. Armando Mateo

2. G is an universal constant, called the constant
of gravitation, and has the value 6.67259x10-11
N-m2/kg2 (3.4389x10-8 lb-ft2/slug2).
Earth this acceleration has the valve
9.80665 m/s2 (32.174 ft/s2).

4. 1. All planets move in elliptical orbits with the
sun at one focus.
2. A line joining any planet to the sun sweeps
out equal areas in equal times.
3. The square of the period of any planet
about the sun is proportional to the cube of
the planet's mean distance from the sun.

5. The velocity of the satellite to stay in orbit is
determined by
1. gravity (the universal gravitational
constant, actually),
2. the mass of the object that the satellite is
traveling around (in most cases, Earth)
and
3. the distance between the center of the
orbit and the satellite (orbital radius)
(which would be the distance from the
center of the Earth to the satellite in most
cases).

6. Exact Satellite velocity
For a constant radius, there is only
one speed that an object can travel to
maintain orbit. If it goes any faster or
slower than this speed it will either go
off into space (faster) or crash down to
Earth (slower).

7. The smaller of the two answers corresponds to Rp, the
periapsis radius. The other root corresponds to the
apoapsis radius, Ra.

11. v=
V=
G = gravitational constant 6.67*10-11
mE = Mass of a planet
rE = the radius of the orbit
rE = h + r
h = height of the orbit
r = the radius of a planet from the
center of the planet to its surface

13. masses M and m moving in circular orbits under
the influence of each other's gravitational
attraction.
where P is the period of revolution

22. According to the heliocentric theory, the earth
is moving at about 1,000 mph at the equator. If
the geostationary satellites were moving, they
would have to move at a speed of about 7,000
mph to maintain a stationary orbit above a
fixed point on the earth. That is about the same
speed as the GPS satellites that orbit the earth
twice a day. However, GPS satellites are
equipped with a rocket engine to
maintain their orbit.