Coud anyone explain why is English word accent traditionally defined as dynamic? Due to some of it's features,history?
That tradition (from the 19th century) first divides languages by applying "tone" to Asian languages (exemplified by Chinese -- they didn't know about Japanese) and "accent" to other things. Then it further subdivides "accent" into "pitch accent" exemplified by Vedic Sanskrit, Classical Greek or Lithuanian, and "stress" or "dynamic" accent for Russian, English, Spanish and so on. The theory (since disproven) was that stressed syllables in "dynamic accent" languages involve greater expiratory force and higher amplitude on the stressed syllable ("power"), but in "pitch accent" languages all there is is a change of fundamental frequency on that syllable.