Homework Help

What is the wavelength of the ocean waves ?Ocean waves pass through two small openings,...

user profile pic

heyitsmegxx | Student, Undergraduate | (Level 2) eNoter

Posted May 1, 2012 at 2:16 AM via web

dislike 0 like
What is the wavelength of the ocean waves ?

Ocean waves pass through two small openings, 27 m apart, in a breakwater. You're in a boat 69 m from the breakwater and initially midway between the openings, but the water is pretty rough. You row 31m parallel to the breakwater and, for the second time, find yourself in relatively calm water.

What is the wavelength of the ocean waves ?

= m

1 Answer | Add Yours

user profile pic

valentin68 | College Teacher | (Level 3) Associate Educator

Posted October 15, 2013 at 12:17 PM (Answer #1)

dislike 0 like

The figure is below. Initially when in rough water the boat is in position A). The difference in path of incoming waves is zero (or an integer number of wavelengths). Finally the boat is in position B. The difference in path of incoming wave is half wavelength.  The length of path of incoming waves in this case is

`p_1 =sqrt(L^2 +(l-d/2)^2) = sqrt(69^2 +(31-27/2)^2) =71.185 m`

`p_2 =sqrt(L^2 +(l+d/2)^2) =sqrt(69^2 +(31+27/2)^2) =82.105 m`

As said above the difference is path is half wavelength.

`P_2-P_1= lambda/2`

`lambda = 2*(P_2-P_1) =2*(82.105-71.185) =21.84 m`

Answer: The wavelength of ocean waves is 21.84 m

Images:
This image has been Flagged as inappropriate Click to unflag
Image (1 of 1)

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes