# Physics in Action

Projectiles

 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 projectile concepts and the use of trigonometry and kinematic equations to analyze the trajectory characteristics of a projectile.

### The Assignment:

Survey your world for some illustration or application of a projectile. The application must involve some real-world situation in which an object's motion can be approximated to be a projectile (due to the fact that air resistance is largely neglectable. Obtain a photograph, movie clip, or magazine clip-out (or photocopy) that provides a visual representation of the physics in action. (HINT: one useful resource is the Guiness Book of Records). You may take photographs or videos of yourself or cut illustrations out of a magazine or newspaper. Once you have identified an example of a projectile, prepare a 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), include a paragraph discussing the physics of projectiles in which you
• define projectile
• describe the magnitude, direction, and changes with respect to time of the horizontal and vertical velocity, the acceleration, and the forces acting upon a projectile during the course of its trajectory
• explain what makes the given representation which you have chosen a projectile
• describe how the time of flight and the range of a projectile can be mathematically determined from a knowledge of the intial velocity (magnitude and direction)
• conduct a mathematical analysis or computation regarding the physical situation in which you use trigonometric functions and kinematic equations to calculate the range of the projectile if launched at the same speed at five different angles ( 30, 40 , 45, 50, 60 degrees); such a computation will require that you make an estimate of a typical initial velocity of the projectile which you have chosen.
• write a concluding paragraph in which you identify which angle produces the maximum range for a projectile and explain why it is that this angle maximizes the range.

### Assessment:

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

### 1. "Technical Merit"

Demonstrated a clear understanding and application of projectile principles 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 a few detrimental errors

6 - 7

Discussion and explanations involve depth and specifics; included an accurate mathematical analysis; 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