speed at different altitudes?

[run1235]

does your speed at different altitudes really change anything? i.e if i'm flying at 200m/s at 5k, am i going slower or faster than 100m/s at 10k?

[Gaarst]

You need to think in terms of angular velocity (or time to cover a given angle of the sphere).

If you're going 200m/s at 5km over the ground, your angular velocity is 2π*v/r = 2π*200/605000 = 0.002 rad/s
If you're going 100m/s at 10km, then: 0.001 rad/s

Even though traveling at lower altitude seem faster, remember that 10km over the surface is not twice as high as 5km, what counts it 610km to the centre against 605km. Now going 100m/s 10km over the surface is as fast as going 200m/s 620km over the surface (610km v 1220km to the centre).

[run1235]

27 minutes ago, Gaarst said:

You need to think in terms of angular velocity (or time to cover a given angle of the sphere).

If you're going 200m/s at 5km over the ground, your angular velocity is 2π*v/r = 2π*200/605000 = 0.002 rad/s
If you're going 100m/s at 10km, then: 0.001 rad/s

Even though traveling at lower altitude seem faster, remember that 10km over the surface is not twice as high as 5km, what counts it 610km to the centre against 605km. Now going 100m/s 10km over the surface is as fast as going 200m/s 620km over the surface (610km v 1220km to the centre).

can you do that in lamens terms XD i'm not really a math geek.

[Blaarkies]

1 hour ago, run1235 said:

can you do that in lamens terms XD i'm not really a math geek.

Imagine standing still on the surface of Kerbin. Click the speed indicator to switch from "Surface" mode to "Orbital" mode. It should show that you are actually moving(relative to the orbital reference)

Now, imagine being at geostationary altitude(2700km ?). How fast should your orbit speed be, so that your "Surface" mode speed shows zero?
Like @Gaarst said, you need to move much faster at higher altitudes to stay above the same spot of ground...and by "higher", I mean 10 times higher than the altitude that planes can fly at