# Calculate the speed of aircraft

1. Jan 21, 2007

### ritwik06

An aircraft flying at an altitude of 10 km finds that the sun is stationary in the sky. Calculate the speed of aircraft.

2. Jan 21, 2007

### DieCommie

Seems like he would be flying as fast as the earth is spinning. Of course he would have to be going a little faster because he is higher up than the surface of the earth.

edit - Oh no, my post has committed some sort of 'Infraction' ! wtf? I guess my thoughts are no good. lol

Last edited: Jan 21, 2007
3. Jan 22, 2007

### ritwik06

Please clarify!! Whats the altitude given for??

4. Jan 22, 2007

### J77

The infraction is that there was no attempt from the OP at a solution!

5. Jan 22, 2007

### Integral

Staff Emeritus
OP,
Use the altidude to find the radius of the circle the plane is flying around.

How long must it take to complete the full circle? If you can answer those questions you can find the speed of the plane.

6. Jan 22, 2007

### DaveC426913

There is a critical piece of info missing: latitude. A plane at 89 degrees latitude will be moving significantly slower than a plane at 0 degrees latitude.

7. Jan 22, 2007

### AngeloG

This is just a logic problem more than numbers really. Given the sun is rising here at say 5 AM PST, it's rising at 5 AM EST [9 AM PST].

That's 4 hours, simply by that we can just get a general idea of how fast it would need to go from here to there. Even then, we can just look at the next time zone and confirm if it's true.

I feel the 10 km in the air doesn't matter; but I could be wrong =).

8. Jan 23, 2007

### ritwik06

9. Jan 23, 2007

### ritwik06

First please clarify this point. If I just rise up to a certain height and stop. Will I move further due to rotation?

10. Jan 23, 2007

### DaveC426913

Well, you will need the latitude, otherwise you can't figure out the speed.