earth

[bassimo]

If a plane flies in a constant speed of 1000 KM eastbound from point A on the equator how much time will it take to reach point A

[gen2]

Look up the equatorial circumference of the earth and divide by the speed.

[Henkle2]

Tried to get us pulled in with the Earth's rotation.

[rojash]

You haven't specified whether that's its airspeed or its groundspeed. In any case KM is not a measure of Speed. Kilometre is abbreviated "km" and Kilometres per hour, "kph"

[R1Geezer]

What gen2 said. There is no benefit from the rotating earth.

[wildwood]

As the equator's length is know to the nearest millimetre, you will also need to add the altitude the plane will be flying at.

[factor-fiction]

Re wildwood's answer- would we need to add something or would the plane's altitude mean that the distance travelled would be less than the same distance at ground level?

[mollykins]

Exactly, you haven't just got the earth's circumference, you have the addeddistance of the climb to cruising altitude and the extra distance of the circumference of the circle you are flying on.

[factor-fiction]

But wouldn't the circumference of the circle you are flying on be less than the size of the equator?

[ChuckFickens]

Of course not, it would be larger, the earths surface would be a smaller circle inside the one the planes path was tracing.

[factor-fiction]

Of course you are are right, chuckfickens. I misread the question and didn't realise the plane was travelling all the way round the world at the equator and returning to the same point.
The point I was trying (and failing) to make is that when travelling between two points A and B the distance on the curve along the ground can I think be more than the straight line distance between two points in mid air (although I accept not directly above as in at 90 degrees relative to the ground). I know what I mean but I clearly wasn't thinking along the same lines as the other posters.