A:
First: It is obligatory upon the Imam to perform the Salah calmly and consider the Ma’mums (persons being led by an Imam in Prayer), so they can perform the pillars of the Salah and its obligations, such as the standing, (Part No. 6; Page No. 311) Ruku‘ and Sujud.Second:
A Ma'mum should follow the Imam and not fall behind him or delay in performing the obligations with the Imam. If they catch up with the Imam when he is performing the Ruku‘ or Sujud, the obligation is to say: "Subhana Rabbiya Al-‘Adhim (Glory be to my Lord, the Most Great)" once during the Ruku‘ and: "Subhana Rabbiya Al-A‘la (Glory be to my Lord, the Most High)" once during the Sujud. The Ma’mum should then follow the Imam and their Salah will be valid.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.