Counting the Rak`ah when joining the Imam during Ruku`

A: A person who pronounces Takbirat-ul-Ihram the moment when the Imam rises up from Ruku` will not be considered as having caught a full Rak`ah with the Imam. The same applies to a person who pronounces Takbirat-ul-Ihram and then pronounces Takbir (saying: "Allahu Akbar [Allah is the Greatest]") for Ruku` and bows down the moment the Imam rises up from Ruku`. The reason is that he did not bow with the Imam for a period long enough to make it a Rak`ah. Thus he has to stand up to offer another Rak`ah after the Imam makes Taslim.However, if a person pronounces Takbirat-ul-Ihram then joins the Imam while in Ruku` for a period long enough for his back to assume the normal bowing position, he, according to the majority of scholars, is considered as having caught a full Rak`ah with the Imam. (Part No. 7; Page No. 315) This is based on the Hadith in which the Prophet states, When you come to prayer while we are prostrating ourselves, prostrate yourselves and do not count it one Rak`ah. He who catches a Rak`ah of the Prayer, he in fact catches the Prayer. (Related by Abu Dawud, Ibn Khuzaymah and Al-Hakim in Al-Mustadrak) Another Hadith also states, whoever attends one Rak`ah (in congregation) is considered to have attended the whole prayer (in congregation). (Related by Al-Bukhari and Muslim)