My first question regards stopping on the word "huwa" in aayah 21 of suratul Hashr (surah 59).

Question

Assalaamu aleikum

My first question regards stopping on the word "huwa" in aayah 21 of suratul Hashr (surah 59).
a)When stopping on that word, does the letter "waw" gets a sukoon since when stopping on a word the last letter gets a sukoon?
b) Also I notice that stopping on that same word (huwa) is done with a two vowel count. Why can't we stop on a 4 or 6 vowel count like the other muduud?

My second question is stopping on the letter "raa" mushaddadah versus the letter "raa"which is not such as in surah Qiyaamah aayah 11 and 12. How should we make the difference in sound when stopping on those respective aayah containing the letter "raa" with a shaddah and the other without?

Jazaakumu lahu khairan
wa salaamu aleikum

Answer
Wa alaikum assalaam wa rahmatullahi wa barakatuh
When stopping on , we have a ha' with a dhammah followed by a , now incidentally saakinah because of stopping. This fulfills the definition of the natural medd, where there is a medd letter (the ) not followed by a sukoon nor a hamzah, nor preceded by a hamzah.  We therefore stop with two vowel counts.
  or the medd caused by an incidental sukoon by definition needs to have one more voweled letter after the medd letter when stopping on the word.  Here there is no letter after the medd letter, so it is only a natural medd and not , so cannot be lengthened more than two vowel counts.

When stopping on a word ending with a mushaddah, we stop with a nabr, or accent to convey the presence of the shaddah.  When stopping on a word ending with a with no shaddah we stop with the sukoon with no nabr.  In both cases there is the mutawassit timing for the.

Please see:
http://www.abouttajweed.com/the-accent-in-recitation-of-the-glorious-qur-an/the-accent-in-recitation-of-the-glorious-quran-p-2.html

Wa iyyaaakum.
Wa assalaam alaikum wa rahmatullahi wa barakatuh