When plate tectonics cause cracks to form,
a. scientists expect entire continents to fall into the earth
b. volcanoes can occur
c. a large rift usually remains and is never filled in
d. most likely the country of mexico will separate from the continental united states

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?