Saturday, August 27, 2016

Olympics in motion pictures

I want to share all of these with my classes during kinematics! The NY Times posted these great Olympic moments in composite pictures. Often simple motion is modeled for students by showing the object in successive photos in the same image. By comparing the distances between the object over time students can get a sense of how quickly it is moving.
When viewing the page you will scroll down but will actually be moved to the right in order to see their full width. Some of the images like the one above seems to be taken in even intervals of time and would therefore be easier to compare. So how can you use them? Let's take a look:

Christian Taylor's gold winning triple jump:
Notice that Taylor's body makes a parabola while he's in mid air for the long jump. What might be surprising is that there is also a clear parabola in his bounds before his big jump. You can trace over the image along his center of mass and show students the parabola shape. You can also point out Taylor's change in position at the end during his jump and discuss his center of mass.

"On match point in their semifinal, the Brazilian team of Barbara Seixas and Agatha Bednarczuk ousted Kerri Walsh-Jennings and April Ross of the United States."
There are great parabolas to be seen in the projectile motion of this volleyball. The volleyballs are closer together at the top of the parabola because it is moving slower and will not travel as far in between each picture.

Derek Drouin's winning high jump:
This image shows Drouin's change in speed as the distance between each changes. There is a great parabola during his high jump and you can see him change the position of his center of mass.

Laurie Hernandez on the balance beam:
I would use this to show students that even when it seems like she's floating on air her center of mass is always supported by a base underneath her. In the first few images show her feet underneath her. The fourth shows Hernandez supported briefly by her hands. As she dismounts you can see a parabolic shape if you follow her center of mass through her flip.

Anytime you can relate what you're studying to the "real world" for your students is a win.