How many kilometers per hour is the wind speed?

Level 6: wind speed 10.8~ 13.8 m/s, speed 39~49 km/h. The umbrella is difficult to carry, the branches are shaking and the wires are whistling. Grade 7: wind speed 13.9~ 17. 1 m/s, hourly speed 50~6 1 km. The whole tree is shaking, so it is inconvenient to walk in the wind. Grade 8: wind speed 17.2~20.7 m/s, speed 62~74 km/h. The branch is broken, and there is great resistance for people to advance. Grade 9: The wind speed is 20.8 ~ 24.4m/s and the speed is 75 ~ 88km/h, which blows down the straw house and roof tiles. 10 class: the wind speed is 24.5 ~ 28.4m/s and the speed is 89 ~ 102km/h, which can blow down trees and destroy ordinary buildings. 1 1 class: the wind speed is 28.5 ~ 32.6m/s, and the speed is103 ~17 km/h, which is destructive, knocking down trees and causing serious damage to general buildings. 12: the wind speed is greater than 32.6m/s and the hourly speed is greater than117km. The waves are huge and destructive. \x0d\x0d\ wind name is equivalent to the physical symbol of wind speed and wave height on land at the height of10m in the open flat \ x0d \ m/s km/h/h (m) \x0d\0 Static wind 0-0.2.