9. a wave on beaver dam lake passes by two docks that are 40.0 m apart.
a. if there is a crest at each dock and another three crests between the two docks, determine the
wavelength.
b. if 10 waves pass one dock every 16.0 seconds, determine the period and frequency of the wave.
.

c. what is the speed of the wave?

Answers:

a) 10 m

b) time=1.6 s, frquency=0.625 Hz

c) 6.25 m/s

Explanation:

a) If there is a crest at each dock and another three crests between the two docks, and the wavelength is the distance between to crests; this means we have in :

Clearing :

b) This part can be solved by a Rule of Three:

If 10 waves ---- 16 s

1 wave -----

Then:

This is the period of the wave

On the other hand, the frequency of the wave has an inverse relation with its period :

This is the frequency of the wave

c) The speed of a wave is given by the following equation:

Finally:

what type of charge does it have? negative

explanation:

v=uf/(u-f)

= 5.-10/(5+10) convex lens has negative focal length