1. Io is the moon of Jupiter. Mass of Jupiter is 317.8 masses of the
Earth. Radius of Jupiter is approximately 72,000 km. Io orbits
around Jupiter at distance 420,000 km above its surface. Find
orbital velocity of Io around Jupiter.
2. Now consider a motion of a satellite around Io. Assume that the
altitude of satellite orbit is 300 km above the surface of Io. Mean
radius of Io is 1821,3 km. Its mass is 8.9319×1022 kg. Find orbital
velocity of the satellite around Io.
3. In northern hemisphere the axis of Earth rotation is pointing
Polaris (Polar star). When our planet rotates it seems that the whole
sky rotates around Polar star while Polar star stays at the same
place giving us direction to the north. It could be and in fact was
used for many centuries for navigation. Unfortunately Polar star
could not be seen from the southern hemisphere. Is there any
analog of Polar star in the southern hemisphere? Find information
in the Internet or books, and describe in a few sentences what can
be used as an analog of Polar star in southern hemisphere.
