ขอบคุณที่เป็นห่วง แต่ฉันยังทำใจไม่ได้ในตอนนี้ ฉันพยายามแล้วเพื่อนSuppose you are riding a bicycle on a day when there is no wind. Although the wind speed is zero (people sitting still feel no breeze), you will feel a breeze on the bicycle due to the fact that you are moving through the air. This is the apparent wind. On the windless day, the apparent wind will always be directly in front and equal in speed to the speed of the bicycle.
Now suppose there is a 5 mph wind coming directly from the north. If you pedal at 10 mph due north, you will feel an apparent wind of 15 mph from the north. But if you pedal 10 mph due south, you will feel an apparent wind of 5 mph from the south. The apparent wind is not only different in speed than the true wind (except when you are standing still), but may also be different in direction.
In these simple examples, the motion is parallel to the true wind which makes it easy to calculate the speed and direction of the apparent wind in relation to true wind speed (relative to the earth). When the motion is not parallel to the wind, one must use trigonometry to calculate the apparent wind. Vector mathematics might also be useful in some cases.