# Physics in Action

Static Equilibrium

 Materials: None Time Allotment: 2 Class Days

### Overview:

This makeup lab is unique from most others in that it does not actually involve a laboratory exercise. Rather, this makeup lab involves the completion of a writing assignment which demonstrates your understanding of static equilibrium and the use of vector physics to analyze physical situations involving objects at equilibrium.

### The Assignment:

Survey your world for some illustration or application of vector physics and static equilibrium. The application must involve some real-world situation in which an object is being acted upon by forces at angles to the horizontal and vertical. Obtain a photograph, movie clip, or magazine clip-out (or photocopy) that provides a visual representation of the physics in action. You may take photographs or videos of yourself or cut illustrations out of a magazine or newspaper. Once you have identified an example of equilibrium, prepare a short, word-processed piece of writing in which you ...

• neatly attach the visual representation to a clean sheet of paper; if your visual representation is a video clip, then dub the video clip onto a clean videotape (the dubbed clip should be no more than 5 minutes and can be as short as a few seconds)
• below the visual representation (or perhaps on the next page), discuss the physics of the phenomenon which you are visually representing; explain the way in which the principles of vector physics and static equilibrium are being illustrated
• conduct a mathematical analysis or computation regarding the physical situation in which you use trigonometric functions to show how and why the object is at equilibrium; such a computation will probably require that you make some estimates of certain quantities in the visual representation (e.g., angle, mass or weight, etc.); once an estimate of the mass or weight of a suspended object is made, the actual tensions can be determined using trigonometric funtions and the estimated angle measurements.

### Assessment:

Your writing assignment/makeup lab will be assessed using the following scoring rubric.

### 1. "Technical Merit"

Demonstrated a clear understanding and application of vector physics by accurately and exhaustively explaining the physics of the situation; included a complex mathematical analysis.

0 - 3

Discussions and explanations are brief and hasty; mathematical analysis or computation may be lacking; effectiveness of writing is hindered by many serious errors; demonstrated little or no understanding of physics

4 - 5

Discussions and explanations are superficial; attention not given to specifics of the physics; too vague;mathematical analysis may be inaccurate or lack organization and clarity; includes only a few detrimental errors

6 - 7

Discussion and explanations involve depth and specifics; included an accurate mathematical analysis/estimation; analysis was clear and organized; demonstrated a perfect understanding and application of physics

### 2. "Artistic Expression"

Writing was word processed and layout was neat, organized, and attractive; writing reflects an organized and sequential flow of ideas and effective transitions; chose a creative illustration of physics.

0 - 2

Layout is sloppy; appears to have been hastily done during the available 15 minutes prior to class; demonstrates a lack of pride in one's work

3 - 4

Word processor was used; layout and/or writing lacks organization and neatness; may not have selected a creative illustration of physics

#### 5

Word processor was used; layout was organized and neat; thoughts were expressed fluently; selected a creative illustration of physics