## Monday, May 12, 2014

### Tracker: camelialim student video ping pong ball filmed in slow motion

Tracker: camelialim student video ping pong ball filmed in slow motion

 http://weelookang.blogspot.sg/2014/05/tracker-camelialim-student-video-ping.html physics of ping pong ball model x = if(t<3.58,0.58*(t-1.869),1.01+0.3631*(t-3.58)) y = if(t<3.58,-1.737E-1+2.473E-1*t-8.133E-2*t^2,-2.761E0+1.015E0*t-9.546E-2*t^2) https://www.dropbox.com/s/9u4hjw26agjm3f0/CameliaLim312_22physics_ptmodel.trz author of video: camelialim author of model: lookang

## Mentoring

i did notice your video at t=0.067 jump frame so it is best not to use that part of the video thinking it is correctly filmed.

i did not notice ““number of reference frames exceeds max (probably corrupt input), discarding one”” don’t worry about it as tracker will do when is best for the video.

i did notice you didn't track accurately, i have re-track as a new object called mass A.

to solve the problem, u need to re-track manually (shift keyboard key and left click mouse)

### the quality can be improved.

using HD to re-flim

1. ensure ball is of a different color from background, for auto-track to work better
2. measure the length near the ball’s travel for example man’s height to reduce parallel error
3. currently you used the side of the ping pong table which may appear longer when calibrating it as the distance of the ball’s travel.

### i recommend analysing the following

1. the motion of the ping pong ball after being hitted
1. a) analyse the motion before bounce on table
1. i) determine useful values of x, vx, and ax=0
2. ii) determine useful values of y,vy and ay=! -9.81 (since the video is slow motion, you need to check do you know the new slow motion framework, tracker didnt detect correctly)
2. b) analyse motion after bounce
1. i) determine useful values of x, vx, and ax=0
2. ii) determine useful values of y,vy and ay=! -9.81 (since the video is slow motion, you need to check do you know the new slow motion framework, tracker didnt detect correctly)
2. construct a kinematics model using the equations using the following hints.
1. x = if(t<3.58,0.58*(t-1.869),1.01+0.3631*(t-3.58))
2. y = if(t<3.58,-1.737E-1+2.473E-1*t-8.133E-2*t^2,-2.761E0+1.015E0*t-9.546E-2*t^2)
3. you can refer to my example TRZ with model

 http://weelookang.blogspot.sg/2014/05/tracker-camelialim-student-video-ping.htmlphysics of ping pong ball modelx = if(t<3.58,0.58*(t-1.869),1.01+0.3631*(t-3.58))y = if(t<3.58,-1.737E-1+2.473E-1*t-8.133E-2*t^2,-2.761E0+1.015E0*t-9.546E-2*t^2)https://www.dropbox.com/s/9u4hjw26agjm3f0/CameliaLim312_22physics_ptmodel.trzauthor of video: camelialimauthor of model: lookang