Speed around earth for constant day light

[aiop]

what speed would you half to obtain going around the Earth to be constantly in line with sun, so it would be day time aways. and how would you go about calculating this. what kinds of equation could you use. Thanks Aiop.

 

[richard.li]

If you wish to to constantly in line with sun, you need to travel at the same speed as the day-night line travels on the earth. You can imagine a line that separate the part of Earth been lighted and not lighted or you can observe it on google earth. This speed certainly is not a fixed value, but longitude by the latitude, and it would be zero at poles during the summer, while it would be maximum at equator. Note that at opposite pole, no matter how fast you travel, you would not see the sun.
If you imagine Earth as a perfect sphere and rotates at its vertical axis, using equation v=pi*D / 24hours will give u a approximate answer, D is a function of latitude,varies from zero at pole and 6600km? at equator?

 

[Isaac0427]

Or you could just look it up. Google the speed at which Earth rotates. If you were at the equator just go that speed in the opposite direction.