Why does true airspeed decrease with altitude?

Related questions

1. What affects true airspeed?
2. Why do airplanes use knots?
3. What is true airspeed vs ground speed?
4. What is true indicated airspeed?
5. How do u calculate speed?
6. Why is ground speed different to airspeed?
7. What's better vs1 or vvs2?
8. Does wind affect true airspeed?
9. Is true airspeed affected by wind?
10. What is airspeed sensor?

Tags

1. #pressure
2. #decrease
3. #words
4. #pitot
5. #molecules
6. #pushed
7. #together
8. #which
9. #other
10. #being
11. #dense
12. #tightly
13. #holding
14. #becomes
15. #airspeed
16. #indicator
17. #altitude
18. #subject
19. #packed
20. #become
21. #increases
22. #drives