## Wednesday, May 14, 2014

### Tracker: KoayTzeMin student video roller blading down a slope motion

Tracker: KoayTzeMin student video roller blading down a slope motion

 http://weelookang.blogspot.sg/2014/05/tracker-koaytzemin-student-video-roller.html physics of roller blading down a slope model vx = 1.384 Fx = g*sin(5.7*pi/180)-k*vx where g = 9.81, k= 0.708 Fy = 0 https://www.dropbox.com/s/84bov2zjxuld6ze/KoayTzeMinrollerbladingmodel.trz author of video: KoayTzeMin author of model: lookang

## Mentoring

this is what teachers are trying to get students be like scientists using the 8 practices to guide everyone.
http://weelookang.blogspot.sg/2013/12/becoming-scientists-through-video.html

firstly, i need you to come up with a question.
Question provided by teacher, materials, or other source
Learner sharpens or clariﬁes question provided by teacher, materials, or other source
Learner selects among questions, poses new questions
Learner poses a question.

### recommendation:

but i also have seen your video and suggest for your consideration the building of a model to represent the motion down the gentle slope.

http://weelookang.blogspot.sg/2014/05/tracker-koaytzemin-student-video-roller.html
physics of roller blading down a slope model
vx = -0.3991
vy = 0.7494
Fx = g*sin(5.7*pi/180)-k*vx where g = 9.81, k= 0.708
Fy = 0
author of video: KoayTzeMin
author of model: lookang

### suggestion:

write down what you think these numbers mean in the model above.
can u suggest a better model (changing the constants to make the model match the real motion better)?
hope u do whatever it takes to be more like scientists!
enjoy!

### Hints:

the axis has been rotated by 5.7 degree so that the motion is purely in the new x direction down the slope is x direction.

the velocity and acceleration appears to fluctuate a lot which normal in real life data due to statistical random errors. Through Data Tools Analysis, you can find out the Curve fits and use these numbers to build a model as a representation of the deep of your understanding and ways to describe the motion.

### Questions:

1. Why does the Fx = g*sin(5.7*pi/180) represent and what does each term mean?
2. Why does the Fx = -k*vx  represent and what does each term mean?
3. putting the 2 terms together ,Fx = g*sin(5.7*pi/180)-k*vx where g = 9.81, k= 0.708, do you know what it represents?

### Models to play with.

in science, using exisiting models or simulations to test real world physics is common practice and we wish students can do more as well.
click on the dropbox links to explore and play if you need some hints.
https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/export/ejss_model_friction/friction_Simulation.htm

 EJSS Static and Kinetic Friction on Incline Plane Model http://weelookang.blogspot.sg/2014/04/ejss-static-and-kinetic-friction-on.html https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/export/ejss_model_friction/friction_Simulation.html source: https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/export/ejss_src_friction.zip author: Francisco Esquembre and recreated on EJSS by lookang