Originally Posted by

**Neod4000** Hello all, I am a British Maths GCSE student working towards the final exam and one day this question cropped up in a mock Maths exam I have done recently. I could not work it out and think it might have cost a percentage of the mark, and was wondering whether it would crop up again.

I try to represent it here and wonder whether any of you guys could help with offering a solution as I could not for revision purposes.

Any help concerning the answer would be greatly appreciated.

Here goes.

The Earth’s circumference around the equator is 24907.55 miles

(1 mile = 1.609344 km)

A plane flies 11km above the surface of the Earth and flies westward following the line of the equator. If the Plane is travelling at 510km per hour, how long will it take for the plane to reach the same place above the Earth’s surface from where it started from? (i.e. at the beginning of the question)

I think you have to consider the rotation of the Earth and km vs miles.

And I think the solution lies in finding the radius of the Earth and adding 11km to it, but I'm not sure.

When it says "the same place above the surface", I believe it is talking about the same place over the Earth's surface at the beginning and at the end as opposed to a complete circumnavigation of the Earth.

i.e. Over Australia at the beginning and at the end.

Any help with this would be greatly appreciated.