To solve this problem we will begin by finding the pressure through density and average depth. Later we will find the Force, by means of the relation of the pressure and the area.

Here,
h = Depth average
= Density
Moreover,

Replacing,


Finally the force



Frequency=f
T=period of motion
f=1/T therefore f=1/2=0.500Hz or 0.5Hz
Hope this helps. Any questions please just ask. Thank you.
Answer:
molecules of elements
Explanation:
An element is formed of one type of atoms. An element is a pure substance. A compound is formed of atoms of different elements chemically combined together in fixed ratio. A molecule of compound has different type of atoms chemically combined. For example, a water molecule is of compound having 2 hydrogen atoms and 1 oxygen atom. A molecule of element has same type of atoms chemically combined. For example oxygen O₂ is a molecule of element.
In the given diagram, same atoms are chemically combined. Thus, these represent molecules of elements.
Answer: The Doppler effect is when the frequency of a sound or light wave is increased or decreased as the observer moves away or toward the source. This is why the pitch of sirens seems to change when they get closer and when they get further.