Which of the following is possible due to longitudinal waves? seeing the color red O riding a wave on a surfboard hearing the sound of the ocean

The distance between the center of a condensation and the center of an adjacent rarefaction is 47.90 cm. If the frequency is 370.9 Hz, how fast are these waves moving? x 10 (select) V cm/s

Please help number 2  2) show that in general the form u = f (x-vt) and u = f (x + vt) are solutions that satisfy the wave equation (the wave equation in the picture)

Fishing boats can be fitted with echo sounders to determine the depth of a shoal of fish below the boat. When activated, reflected waves return to the echo sounder after 0.19 s (reflected from the fish) and 0.28 s (reflected from the ocean floor). If the speed of sound in seawater is 1490 m/s, determine the distance between the ocean floor and the shoal of fish.