Look up the distance to Neptune (in miles) and divide by 10,000. The answer will be in hours. Convert that to years if you wish.
The distance to Neptune varies depending upon where earth and Neptune are in their orbits. Just use the average value of the Neptune-sun distance.
http://wiki.answers.com/Q/How_far_is_Neptune_from_Earth
how long would it take to trvel to neptune going 10000 mph
1 answer