So we change the shuttles' speed standard. There is a 30cm distance between eachspeed. Shuttle speeds are ideal for different parts of the world. For example, shuttles with Speed 76 are used in China during the summer and 77 during the winter months. Speed 73-74 would only be played in high altitude area as Yunnan Province in China and Colorado Springs in U.S.A. or high temperture area as Johannesburg in South Africa.
Shuttlecocks also have rotational speed which is crucial for the stabilities.
For shuttlecock stability at speeds higher than Mach 0.65, the upper body flaps were moved from the average position of 11.8 degrees to 20 degrees upward from the body surface. If you ask what's the maximum speed in kilometers per hour for the shuttlecock ever got regardless circumstance, please check the Guinness Book of Records. The acceleration due to gravity is constant. The acceleration due to air resistance increases as the shuttlecock picks up speed through the air. All rights reserved.