Would sound travel faster in a thick piece of metal (high density) or a large hollow piece of metal (low density)?

See the explanation below

Explanation:

The speed of sound waves can be calculated using the following equation:

Let's do the exercise of comparing two materials one denser than the other, as is steel and aluminum

ro_steel = 7500 [kg/m^3]

ro_aluminum = 2700 [kg/m^3]

E_steel = 200 [GPa]

E_aluminum = 70 [GPa]

Now replacing the values in the equation for each material.

And for the aluminum

In this way we can see that sound propagates faster in denser materials.

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.