Which best describes the wavelength of a simple wave?

A. The distance from the crest of a wave to the crest of the
next wave
B. The distance from the crest of a wave to the trough of the
next wave
C. The number of waves that pass a certain point in a minute
D. The speed at which the wave travels in m/s

In an old-fashioned amusement park ride, passengers stand inside a 3.0-m-tall, 5.0-m-diameter hollow steel cylinder with their backs against the wall. the cylinder begins to rotate about a vertical axis. then the floor on which the passengers are standing suddenly drops away! if all goes well, the passengers will “stick” to the wall and not slide. clothing has a static coefficient of friction against steel in the range 0.60 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70. part a what is the minimum rotational frequency, in rpm, for which the ride is safe? express your answer using two significant figures. f f = rpm