2 men are fishing from small boats located 36m apart. Waves pass through the water, & each man's boat bobs up & down 15 times in 75s. At a time when 1 boat is on a crest, the other 1 is in a trough, & there is 1 crest between the 2 boats.

Question

f=15/75=.2Hz
Wavelength=36m
V=f(wavelength)=.2(36m)=7.2m/s

Is that correct? I'm most concerned about the wave length. If there's 36m between them, & one full wave between them, then wavelength must = 36m right?

Thanks for your time! :)

Answer 1

from reading the problem, it looks like the boats are one and a half waves apart

crest and trough, with one crest in between

Answer 2

I'm super confused about it because I asked my teacher how there could be 1 crest between a crest & trough
she said "There's 1 crest between them so they are further apart"
So I clarified that "that means there's 1 crest & 1 trough between? thanks" & she just said you're welcome...

Answer 3

boat on crest
... half wavelength
trough
... half wavelength
crest between boats
... half wavelength
boat in trough

the crest between the boats is the max of the wave that the 2nd boat is in the min of (trough)

that is a half wavelength

from the crest between to the crest the 1st boat is on is a full wavelength

the boats are one and a half wavelengths apart

Answer 4

Ok, thank you very much :)