Pedagogy in Action > Library > Using Direct Measurement Videos to Teach Physics > Example Activities > Direct Measurement Video of a Girl on a Trampoline

Direct Measurement Video of a Girl on a Trampoline

Beth Marcure

Summary

Screen shot from a video of person jumping on a trampoline (Quicktime Video 7.7MB Jul9 12)
This clip shows a person jumping on a trampoline. When studying conservation of energy, a common example is a ball being tossed into the air. This is a real life example of a girl jumping on a trampoline that we can use to find her velocity as she leaves trampoline. Using the handout provided students will be able to determine her velocity when she leaves the trampoline based on the fact that they can calculate her gravitational potential energy at two different locations. To enable students with there calculations there is a ruler included in the video.

Learning Goals

Students will be able to use a real-life example to study the concept of conservation of energy.

Students will be able to obtain data from the movie and using the conservation of mechanical energy be able to determine the velocity of an object in motion.

Context for Use

This lesson is intended for use in a physical science class or an introductory physics course, high school level. It is intended for use when the students are learning about Conservation of Mechanical Energy.

Description and Teaching Materials

In this video clip it shows a girl jumping on a trampoline. When looking through the video one frame at a time, students can use the grid on screen to determine the height at which she is at to determine her gravitational potential energy. Students will use the height at which she leaves the trampoline, with respect with the ground, and her maximum height to calculate her potential energy at two locations. With this information, students can use the conservation of energy equation to calculate her velocity as she is leaving the trampoline.

This worksheet is intended to use after the students have become familiar with the conservation of mechanical energy equations, it provides the students with some guidance on how to solve for the unknowns. This worksheet could be modified to provide students more guidance if needed or using to introduce the concept of conservation of mechanical energy. Less instruction could be used if you were using this video for an introductory physics course to allow more critical thinking skills and problem solving.
Student Handout (Microsoft Word 2007 (.docx) 17kB Jul13 12)

Here are sample solutions to the student worksheet.
Sample Solutions (Microsoft Word 2007 (.docx) 43kB Jul13 12)

video of person jumping on a trampoline (Quicktime Video 7.7MB Jul9 12) Here is a link to the video where you can download it to your computer.

Teaching Notes and Tips

When using the video clip for class it is recommended that you first download the video to your computer and use QuickTime to view the videos. This is recommended because QuickTime enables you to be able to advance the video forward frame by frame, making it easier for the students to determine the height of the girl. The reason why you need to download the video to your computer is because QuickTime only lets you advance frame by frame when the video is on your computer. Computers are needed for the only the first part of this activity so they can view the video to make their calculations. Computers are only needed so students can determine the height in which the girl is at in the two locations. If computers are not available for your students another option would be to project the image up on a screen and find the heights as a class.

Assessment

One way to assess students understanding of the concept of Conservation of Energy is to give students a similar video activity as this. Another way to assess students is to give them textbook problems to check there level of understanding.

References and Resources

Direct Measurement Video Library

Student Handout (Microsoft Word 2007 (.docx) 17kB Jul13 12)

Sample Solutions (Microsoft Word 2007 (.docx) 43kB Jul13 12)


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