Pacing is what keeps people reading a book. If the pace drags, the book can be put aside. I was sorting through my books the other day trying to decide which ones to keep and which ones to send to other lives. These are all novels. I picked up one and saw that I had only read about thirty pages. Thinking I had a new book to read, I sat down and began to read. The first three chapters that I'd read dragged and I knew I wasn't getting into the story by that time so that book went to another life.
Scenes are part of pacing. Each scene has a beginning, a middle and an end. There's one thing different for each scene must have an ending that draws the reader to turn the page and read the next scene. Again I'm using Becoming Your Own Critique Partner written by Jane Toombs and myself as the writing book for this session.
The pacing of individual scenes can vary depending on the writer's purpose for the scene. What purpose have you designed for the scene. Characterization, plot development, or for needed information. Choosing the length of sentences can either speed or slow the scene.
What kind of scene is needed. There are four. Mood or tone, action, reaction or genre. Mood or tone means things like mysterious, romantic, funny. Action scenes are ones like chases, fights, decision making as examples. Reaction scenes are often slower, use much internal dialogue and generally short. Genre - each genre has a definite style of pacing with a number of variations. A long and detailed love scene in the middle of an action adventure can throw the pacing off. This is just one example.