4. In question 3, will the measured wavelength of the sound be longer or shorter than if both you and the train were at rest?
a) longer because the pitch is higher
b) shorter because the pitch is unchanged
c) shorter because the pitch is higher
d) the same because only the pitch changes, not the wavelength

Afisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. it takes a time of 2.20 s for the boat to travel from its highest point to its lowest, a total distance of 0.670 m . the fisherman sees that the wave crests are spaced a horizontal distance of 5.80 m apart. (a) how much is the wavelength? (b) find the period of the wave. (c) how fast are the waves traveling? (d) what is the amplitude a of each wave?