In the word "nurse," we can break it down into two syllables. The first syllable is pronounced as /nɜː/ and the second syllable is pronounced as /rs/.
To pronounce the first syllable, we start with the sound /n/. This is a voiced alveolar nasal sound, which means that the air passes through the nose as we pronounce it. The tongue is pressed against the alveolar ridge, which is the bumpy part behind the upper teeth.
Next, we move on to the vowel sound /ɜː/. This is an open-mid central unrounded vowel sound. To pronounce it, the tongue is relaxed and the mouth is slightly open. It is similar to the sound in the word "bird" or "herd."
Lastly, we have the sound /rs/ in the second syllable. This is a combination of two sounds, /r/ and /s/. The /r/ sound is a voiced alveolar liquid sound and the /s/ sound is an unvoiced alveolar fricative sound. The tongue in the /r/ sound is curled slightly and the air passes between the sides of the tongue and the upper molars. The /s/ sound is produced by forcing the air through a narrow gap between the tongue and the alveolar ridge.
So, the phonetic transcription for "nurse" is /nɜːrs/.