Period, Frequency, Wavelength and Velocity

Question

James is lying on his body board out in the surf. 12 waves pass him every minute. These waves are about 14m apart from one crest to the next and they rise 2 meters above the normal water level.

a) Calculate the following:

(i) Period

(ii) Frequency

(iii) Wavelength

(iv) Velocity

b) Assuming that water waves are transverse waves, when each wave passes him how much does James move horizontally and vertically?

Answer 1

i) The period T = 1/f  (where f is the frequency) = 1/12 minute = 0.083 minute or 0.083*60 = 5 seconds

 

ii) frequency = 1/T = 1/5 or 0.02 seconds

 

iii) Wavelength = 14 m, the distance between similar points on successive waves

 

iv) Velocity, v = wavelength/time for one wave (T) = 14/5 = 2.8 m/s

 

b) 14 m horizontally and 2 m vertically at the wave's crest (both do not occur at the same instant)