Learn Dynamics Of A Scene And Rhythm For A Great Acting Performance

An actor's great performance depends on:

1. Learning the DYNAMICS of a scene
2. RHYTHM required by a character to meet the changes in the dynamics of a scene

What are "dynamics" in a scene?

A good scene (screenplay) has within it some changes or dynamics. This means there are somethings  for example emotions, activities, story different at the end of a scene than at the beginning.
These changes constitute DYNAMICS.
The "characters" at the end of a scene are different than they were at the beginning. This is because shifting and changing emotions or activities command viewers attention!
Example: Here is a small scene (not a screen play or a script) to explain to you. The dynamics of this scene are showed in red.
"Rita is in her sitting room with her husband Ramesh and entertaining her friend Sonia. Rita has a 2 years old son. Everybody is in jovial mood.
Suddenly, her son crosses the room running following a ball. Ramesh and Rita started laughing looking at their son feeling proud. After few moments there was a loud thud followed by crying of Rita's son. A momentary silence in the sitting room. The expressions of everybody changed and turned into a fear. Rita and Ramesh sat paralyzed for a moment and then Rita got up quickly and ran towards another room where her son had gone and at the same time telling Ramesh to be with Sonia.
Ramesh sits back and looks at Sonia.
After few minutes they here the voice of Riota telling them that everything is okay, nothing to worry. Ramesh and Sonia looks at each other relieved
Rita enters into sitting room back with her son  with a relieved face."

If you analyze the above in red you will understand the "dynamics" of this scene. The emotions at the beginning, middle at the end are different. 
For an actor to give a great performance it is essential that he/she understands these dynamics and prepares character's rhythm accordingly

What is "Rhythm?

Every individual has his/her own rhythm of speaking, walking and tone that is slower or faster on different life situations, from moment to moment. However, it could be slower or faster. For example JOY, ANGER OR TERROR imply faster rhythm where as  sadness requires slower rhythm or silence in SHOCK, depending upon what is affecting them
A faster or slower rhythm, created by an actor has to be in totality that is your entire instrument must be coordinated like body, voice, gestures walk etc. If a control of an emotion is a part of a role e.g. "anger control", the it should be with deliberate physical movements or rhythmic changes.
"STOP" an action momentarily if you want the viewers to know that you have been struck by a stimuli and then cross the bridge from one emotion to another slowly, say give a minimum of 10 seconds