Jun 17 2008

Reel Projectiles

Students use slow-motion movies to help understand the principles of physics.

Mechanics is a core subject in any high school physics course. Projectile motion is a popular mechanics topic that appeals to students, perhaps because of its ubiquitous nature in their lives. From footballs to hacky sacks, students are as familiar with projectiles as they are with cell phones and MP3 players. This lesson capitalizes on student interest in projectiles in order to investigate their motion characteristics.

Lesson Description:

This inquiry-based lesson centers on the question: What are the motion characteristics of a projectile? Students begin their investigation with a web-based activity that uses an interactive Shockwave movie. The movie animates a projectile’s motion, allowing students to alter the launch’s height, speed and angle. A vector and numerical representation of the motion is displayed in real time. This allows students to view the changes (or lack of changes) in the horizontal and vertical velocity and acceleration of the projectile.

Students then use LoggerPro software to conduct a frame-by-frame analysis of a short video clip of a basketball’s motion. Using intuitive on-screen tools, students click on the ball’s position in each consecutive frame. Numerical information about the position, velocity and acceleration during the ball’s flight is automatically gathered and graphically displayed with respect to time. Students record data and observations in their lab notebooks. They then draw conclusions about a projectile’s motion characteristics, citing evidence from both the web-based animation and the real-world motion of the basketball.

As a follow-up to this lab investigation, students are assigned readings about projectiles from The Physics Classroom tutorial found at our school website.

Subject Area:

This lesson is designed for a high school physics course.


This lesson addresses the following National Science Education Standards:

  • Students should develop an understanding of forces and motions.
  • Students should develop abilities necessary to do scientific inquiry.
  • Students should use technology to improve investigations.
  • Students should formulate and revise scientific explanations and models using logic and evidence.


The Shockwave movie used for this activity is found at: gbs.glenbrook.k12.il.us

LoggerPro software is available from Vernier Software and Technology (www.vernier.com). The software can import QuickTime movies for frame-by-frame analysis. Several dozen prepared movies are shipped with the software. LoggerPro also interfaces to Vernier’s popular LabPro data collection interface and associated probeware for biology, chemistry and physics.

Physics Classroom Tutorial: gbs.glenbrook.k12.il.us

Grading Rubric:

Students are in the habit of recording their lab investigations in a lab journal. Their data, analysis and conclusions should address the question posed at the onset of the lab: What are the motion characteristics of a projectile? Students are assessed based upon the organization and accuracy of their observations and the depth and quality of their explanations.

Teaching Tips:

  • Allow students to collect their own video footage. Interest level rises considerably when the object to be analyzed is one they threw, shot, hit or kicked. The angle at which the motion is filmed should be perpendicular to the plane of motion of the object. A 1-meter stick or other object of known length should be visible in the video to provide a measurement standard.
  • Provide students with a short handout or demonstration describing LabPro’s user interface. Once familiar with the interface, students are equipped to answer the question posed at the onset of the lab.