C
The atomic mass is the sum of the number of neutrons and protons.
Answer
figure it out are you d*mb
Explanation:
ha-ha
Every 10.0 seconds, a crest of the wave passes the pier. This means that the period of the wave is exactly 10.0 s:

which means that the frequency of the wave is

The wavelength of a wave is related to its frequency by the relationship

where v is the speed of the wave.
In this problem, v=5.6 m/s; if we use the previous formula, we find the wavelength of the wave:
just analyze it in this way:
20cos30*=10( radical 3 )
20sin30*=10