One of the tricky things about learning to sail is distinguishing the “true wind” from the “apparent wind.” The true wind is the velocity of the air relative to the water, whereas the apparent wind is the velocity of the air relative to the sailboat. The figure shows three different directions for the true wind. 

(a) In each case, draw a vector diagram to establish the magnitude and direction of the apparent wind. 

(b) In which of the three cases is the apparent wind speed greater than the true wind speed? (Assume that the speed of the boat relative to the water is less than the true wind speed.) 

(c) In which of the three cases is the direction of the apparent wind direction forward of the true wind? [“Forward” means coming from a direction more nearly straight ahead. For example, (1) is forward of (2), which is forward of (3).]

Transcribed Image Text:

Velocity of boat relative (1) to water (2) (3)