The word 'physics' is a noun, a word for the science or study of nature and properties of matter and energy; a word for a concept; a word for a thing.
Physics is naturally a part of the field of natural sciences, as it involves the study of the natural world and its fundamental principles. It also intersects with other disciplines such as mathematics, engineering, and astronomy.
"Wavelength" is a noun.
An adjective
Dew is a noun.
"Sunshine" is a noun.
It can be an adjective if the sentence is something like "We faced physical challenges today." It can also be a noun if you're saying "I'm going to the doctor for my physical."
Speech sounds are specific sounds. The word physics would be pronounced as: fis - ics or fiz - ics
Thermodynamics is part of physics.
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
what part of speech is beneath
adverb
The part of speech for "explicit" is an adjective.
The part of speech for "lecturer" is a noun.
The part of speech for "rapid" is an adjective.
The part of speech of "came" is a verb.