7 什么比猎豹的速度更快

Lesson Seven

What Is Faster Than Cheetah

1. Maybe you run very fast.

2. But you can’t win if you race against cheetahs and ostriches.

3. When people are struggling to run, the maximum speed can reach 24 km/h.

4. That is a far cry from the speed of an ostrich.

5. The maximum running speed of ostrich is 72 km / h.

6. Among the two legged animals, ostrich should be regarded as the world champion of running.

7. The animal that can run faster than ostrich is cheetah.

8. The maximum speed of cheetah can reach 110 km / h.

9. Cheetah is the fastest animal on land!

10. But the speed with which a peregrine falcon swoops downward is faster, exceeding 320 km/h!

11. This speed is two to three times as fast as a car on a highway!

12. It dives faster than any other animal can run.

13. However, the peregrine falcon is not as fast as an airplane!

14. At the altitude of jet aircraft, the speed of sound transmission is about 1050 km/h, and some high-speed jet planes fly several times the speed of sound.

15. If you shout at a person moving at supersonic speed, he can’t hear anything.

16. Because the voice can’t catch up with him.

17. It is definitely fast enough to travel by jet aircraft.

18. But if you want to go to the moon, you need a faster ride.

19. Yes!

20. It is a rocket.

21. In order to get rid of gravity and fly into the vast space, the speed of rocket is much faster than that of jet aircraft.

22. The maximum speed of the rocket can reach 40,000 km/h, which is more than 30 times the speed of sound.

23. After entering space, even if the engine is turned off, the rocket can continue to move forward.

24. Look!

25. What is the thing whistling in front of you?

26. Compared with its speed, the rocket seems to be at rest.

27. That’s a meteoroid!

28. Meteoroid is a small celestial body in space.

29. The maximum velocity of some meteoroids can reach 250,000 km/h, which is more than six times the speed of a rocket.

30. Now, you must think that meteoroids are the fastest objects that people can see.

31. But there’s something much faster than a meteoroid, and it’s just all around us.

32. As long as we press the flashlight switch, a beam of light will appear immediately.

33. The speed of light is amazing, about 300,000 km/s, thousands of times faster than the speed of meteoroids!

34. If we move at the speed of light, we can go around the earth’s equator about seven times in a second!

35. Scientists believe that light travels the fastest.

36. It is incredible that the fastest thing in the universe can be easily held in your hand!