f = PN/120 where f is frequency of power supply, P is number of poles in the machine and N = speed in rpm. So, Synchronous speed N = 120f/P. Thus for 50 Hz supply, 2 pole machine; synchronous speed = 3000rpm. ETRICAL
Within our solar system quite a bit of exploration has been done by spacecraft including orbiters and landers. Planets outside our solar system will be difficult or impossible to explore with spacecraft in our lifetimes, so astronomers and astrobiologists use other techniques to search for signs of life on these planets. In particular, astronomers are interested in planets within the habitable zone of stars.
The charted regions of the Solar System comprise the Sun, four rocky inner planets (Mercury, Venus, Earth & Mars), the asteroid belt and four gas giant outer planets (Jupiter, Saturn, Uranus & Neptune).They are called inner and outer planets because or their orbital position near to or far away form the Sun.upiter is a planet and it goes in this order: Mercury, Venus, Earth, Mars, (those were the inner planets and now are the outer planets.)Jupiter, Saturn, Uranus, Neptune and if Pluto were a planet it would be last but you should remember that it is not.