Video Analysis – part 2

1. Video Analysis – part 2 Take Notes!!!

2. Analyzing Momentum and Energy Using Video on LoggerPro How much kinetic energy and momentum is transferred to linear motion in an elastic collision, and in an inelastic collision?

3. What do you need to accomplish this task? Data needed: think… Method/setup for collecting data: Math/equations: Presentation of your evidence:

4. Your individual write-up in PowerPoint • Your final project will be turned in to the Dropbox by the start of school Monday. • There will be 8 slides only. No more, no less. • Opening slide will have your name on it. There will be a picture of the elastic collision from loggerpro and the graphs (with slopes). There will be a BRIEF description of the collision. • Next slide is the data table • Next slide is the momentum write-up and.. • Last slide is the kinetic energy write-up • Now repeat this for the inelastic collision. (4 slides)

5. Inelastic Collision from Ima Student0.25kg cart on right (-0.42m/s), 0.75kg cart on left (0.57m/s), both moving towards each other and then moving to the left at -0.87m/s after the collision

6. Inelastic Collision Data & Calculations example

7. Example of Momentum • The cart on the right was going -0.480m/s before colliding with the cart on the left that was at rest. The collision was inelastic. The two carts velocity was -0.236m/s after the collision. Both these velocities were determined by finding the slopes of the best-fit line on the position/time graph. • By the conservation of momentum, the total momentum before the collision(.75kg x -.480m/s = -.360kgm/s) should be equal to the momentum afterwards (1.5kg x -.236m/s = -.354kgm/s). • There is an error of 1.7%. (. 006/.360 x 100) • We have less momentum after the collision. We feel that the best explanation for this error is ________________

8. Using the camera No camera movement If the camera moves the data is worthless Shoot perpendicular to the motion Or problems with parallax Shoot extra footage Lead in and out for 3 seconds Do not shoot for more than 10 seconds to keep file size down Have a known distance in the shot A ruler/meter-stick works well It HAS to be the same distance to the camera as the object in motion

9. Downloading video: • Plug the Flip-camera into the USB port on the computer • Select “Open folder to view files” from the pop-up • Open the “DCIM” folder • Open the “100VIDEO” folder • Drag your movie clip onto the desktop (you MUST save this into your Physics folder before doing video analysis) • You may want to rename them inelastic and elastic collision…

10. Using the camera No camera movement If the camera moves the data is worthless Shoot perpendicular to the motion Or problems with parallax Shoot extra footage Lead in and out for 3 seconds and keep it short! Have a known distance in the shot A ruler/meter-stick works well It HAS to be the same distance to the camera as the object in motion

11. Share it with your group • In your folder within the physics folder • All of you can access this now from anywhere in the building. • Always save all files here and work on video files on the desktop for best results • Thumb-drives? • Email • Good luck… • Burn it