But, A rising action is usually when the story would start to get tense an example from "Of mice and men" When Curley's wife was getting choked by Lennie, It was like a rising action, As it was tense and could leave you on the edge of your seat
Wait but what are the questions
The answer is Line 4
Answer: ^^
Often times, the actual object is much more expensive to create. That's why many designers and engineers create a model to represent their ideas to a group. The model is much cheaper and faster to create, especially if it needs tweaking multiple times. Also, that model can have working parts - you could take it apart to show the inside/cross-section or have interactive sections that allow easier presentation of your idea. Those are things you can't accomplish with an actual object.