Why do commercial planes fly at 35,000 feet?

Question

Why do commercial planes fly at 35,000 feet?

In: 13

Answer 1

The higher you go the thinner the air, this means lower resistance and you can go faster using less fuel

however thinner air also means less air, and this means less air for the engines and less air for the wings to work, so you also can’t go too high

Answer 2

The higher you go the thinner the air, this means lower resistance and you can go faster using less fuel

however thinner air also means less air, and this means less air for the engines and less air for the wings to work, so you also can’t go too high