Why do jets fly at 35000 feet?

Related questions

1. Do airplanes have speed limits?
2. What is the unit of speed?
3. Do planes use knots?
4. Is speed same as ground speed?
5. Can planes fly faster to make up time?
6. Why is ground speed different to air speed?
7. Why does TAS increase with temperature?
8. What is the difference between air speed and ground speed?
9. Why do planes fly faster at higher altitudes?
10. What speed do airplanes land at?

Tags

1. #faster
2. #easily
3. #behind
4. #planes
5. #central
6. #thinner
7. #money
8. #reasons
9. #therefore
10. #altitude
11. #aircraft
12. #climbed
13. #better
14. #travel
15. #every
16. #saving
17. #higher