Waves are observed passing under a dock. wave crests are 8.0 meters apart. the time for a complete wave to pass by
is 4.0 seconds. the markings on the post submerged in water indicate that the water level fluctuates from a trough at
6.0 meters to a crest at 9.0 meters. calculate the velocity of the wave.
1.0 m/s
5.4 m/s
2.6 m/s
2.0 m/s

Option D

2 m/s

Explanation:

The speed is given by distance/time

The complete wave has a distance of 8 m (This is the wavelength)

Time taken for complete wave is 4 s

Therefore, velocity= 8 m/ 4 s= 2 m/s

The amplitude is the distance between crest and trough hence 9 m- 6 m= 3 m

Frequency is 1/period and in this case period is 4 s hence frequency= 1/4= 0.25 Hz

Essentially, what we wanted is velocity