**urgent** now lets look at a skydiver who jumps out of a plane that has a forward velocity of 40 m/s. ignore air resistance. after 1 second, what is the skydivers downward velocity?

If there's no air resistance, then the diver keeps moving horizontally at 40 m/s, even after s/he jumps out of a perfectly good airplane.

Also, gravity ADDS 9.8 m/s of downward speed for every second the diver falls.

One second after leaving the airplane, the diver is moving horizontally at 40 m/s, and moving vertically downward at 9.8 m/s .

The question asks for the "downward velocity".  That's 9.8 m/s .

The diver's TOTAL velocity is

                       √ (40² + 9.8²)

                   =  √ (1,600 m²/s² + 96.04 m²/s²)

                   =  √ (1,696.04 m²/s²)

                   =        41.2 m/s  in some direction between
                                           straight forward and straight down.

Lexy is correct because angle r is between the incident wave,  n  = 0, and a diffracted wave.