5. a person fishing from a pier observes that four wave crests pass by in 7.0 s and estimates that the distance between two successive crests is 4.0 m. the timing starts with the first crest and ends with the fourth. what is the speed of the wave? listnumbered listsuperscriptsubscript

v= 1.71 m/s

Explanation:

Given that

Distance between two successive crests = 4.0 m

 λ = 4 m

T= 7 sec

T is the time between 3 waves.

3 waves = 7 sec

1 wave = 7 /3 sec

So t= 7/3 s

We know that frequency f

f= 1/t= 3/7 Hz

Lets take speed of the wave is v

v= f λ

f=frequency

λ=wavelength

v= 3/7 x 4 = 12 /7

v= 1.71 m/s

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be