El planeta Urano completa un periodo de traslación solar en 83,75 años; su radio es de 25.559 km y su masa se calcula en 8,7. 10^25 kg. CALCULAR:
a) distancia al sol
b) fuerza de atracción gravitatoria con la que el sol lo mantiene en órbita
c) gravedad en su superficie
d) el peso de una persona que en la tierra pesa 80 kg.
e) la velocidad a la que se debería poner en órbita una sonda a 25.000 km de altura sobre su superficie.

AYUD

Neptune is the eighth planet from the sun. it was the first planet to get its existence predicted by  mathematical calculations  before it was actually seen through a telescope on sept. 23, 1846. irregularities in the orbit of  uranus  led french astronomer alexis bouvard to suggest that the gravitational pull from another celestial body might be responsible. german astronomer johann galle then relied on subsequent calculations to   spot neptune via telescope. previously, astronomer galileo galilei sketched the planet, but he mistook it for a star due to its slow motion. in accordance with all the other planets seen in the sky, this new world was given a name from greek and roman mythology — neptune, the roman god of the sea.