## Wednesday, April 30, 2014

### Tracker: natashataiqianhui student video bouncing ball filmed horizontally by camera

natashataiqianhui

 http://weelookang.blogspot.sg/2014/04/tracker-natashataiqianhui-student-video.html bouncing ball video https://www.dropbox.com/s/vz3dbyvlvpe1m7s/natashataiqianhui_304_18_physicstrackerfamodel.trz author of video: natashataiqianhu, author of model: lookang (only for the first 3 bounces is added)

## mentoring suggestion:

good effort.
look at the TRZ file to see how scientists use models (mathematical equations to predict and explain).

question for u to think about.
1. explain what does this model do
y = if (t<0.4,0-0.75*t-5.351*t^2,if(t<1.202,-3.275+8.052*t-5.126*t^2,if(t<1.95,-12.24+15.44*t-4.962*t^2,-0.95)))
for the first three bounce.
2. after you understood point 1, can u add the 4th bounce ?
3. suggest why this is a deep way to learn physics.

enjoy!

## Explanation of the model:

kinematics model
y = if (t<0.4,0-0.75*t-5.351*t^2,if(t<1.202,-3.275+8.052*t-5.126*t^2,if(t<1.95,-12.24+15.44*t-4.962*t^2,-0.95)))

in a nested loop,
if time is less than 0.4, then y is equal to 0-0.75*t-5.351*t^2 as coefficients are determine from the data analysis power 2 fit
if time is less than 1.202, then y is equal to-3.275+8.052*t-5.126*t^2 as coefficients are determine from the data analysis power 2 fit
if time is less than 1.95, then y is equal to --12.24+15.44*t-4.962*t^2 as coefficients are determine from the data analysis power 2 fit
else don't bounce y = -0.95