Monday, May 28, 2012

Physics by Inquiry with Computer Models – Update Jan-May 2012

Physics by Inquiry with Computer Models – Update Jan-May 2012

Physics by Inquiry with Computer Models – Update Jan-May 2012.

All our computer model are shared here to scale up to ALL JC's and schools in Singapore who find our work useful.

Thursday, May 24, 2012

Wee L.K., Charles Chew, Goh G.H.,Lee T.L.,Samuel Tan (2012) Using Tracker as a Pedagogical Tool for Understanding Projectile Motion

Wee L.K., Charles Chew, Goh G.H.,Lee T.L.,Samuel Tan (2012) "Using Tracker as a pedagogical tool for understanding projectile motion." Physics Education 47(4): 448.

Figure 1.    World view of a projectile motion as in the video ‘’ shown with 0 fade using the ghost filter.

Another journal paper accepted :)

Loo Kang WEE1, Charles CHEW2, Giam Hwee GOH3, Samuel TAN1, Tat Leong LEE4
1Ministry of Education, Education Technology Division, Singapore
2Ministry of Education, Academy of Singapore Teachers, Singapore
3Ministry of Education, Yishun Junior College, Singapore
4Ministry of Education, River Valley High School, Singapore,,,,

This paper reports the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When computer model building learning processes is supported and driven by video analysis data, this free Open Source Physics (OSP) tool can provide opportunities for students to engage in active inquiry-based learning. We discuss the pedagogical use of Tracker to address some common misconceptions of projectile motion by allowing students to test their hypothesis by juxtaposing their mental models against the analysis of real life videos. Initial research findings suggest that allowing learners to relate abstract physics concepts to real life through coupling computer modeling with traditional video analysis could be an innovative and effective way to learn projectile motion. 

Keyword: Tracker, active learning, education, teacher professional development, e-learning, open source physics, GCE Advance Level physics

Current status and history
DateTask descriptionDeadline date/Status
23/05/2012Check proof28/05/2012
29/02/2012Reports for Editor-in-Chief's recommendationReport received
10/02/2012Author revision requiredRevised manuscript received
13/01/2012Original manuscript to refereeReport received

Proof for correction

Article ID:



Using Tracker as a pedagogical tool for understanding projectile motion


Mr Loo Kang Wee et al

Article status:

Awaiting proof corrections

Please check your proof and submit your proof corrections using the fields below.

Queries for IOP paper 419619
Journal: physed
Author: LKWee et al
Short title: Using Tracker as a pedagogical
tool for understanding projectile motion
General changes required.

Typo error where  changes are suggested after the end of the = sign.
Page1 =  =
Page 2
Equation 2 has a full-stop " ." , suggest remove it.
after Equation 4, 6 lines down, "3nt"   = "current"
Page 7:
New Paragraph Heading: "A" capital  seems wrong.
Teachers’ reflection on using the dynamic pArticle model = Teachers’ reflection on using the dynamic particle model
Page 8
Author name the error is "Giam Hwee Gohc" it should be "Giam Hwee Goh"
the is no extra "c" at the end of the co-author's last name.

Page 2
Query A:
Author: Please check and clarify the first
sentence of the captions of figures 2 and 3.
Data tool display real data mass A y versus t =  Data tool display of mass_A showing y versus t
Figure 2: Line 4: b = -2.379 should be b = 2.379

the final statement could look like this.
Figure 2. Data tool display of mass_A showing y versus t view where the parabola fit equation of
y = a2t + bt + c is used with parameters a = −5.038, b = 2.379 and c = −0.003. By comparing with
equation (4y), it is determined that gy = −10.08 m s−2 and uy = 2.379 m s−1 respectively

"Figure 3. Data tool display real data mass_A of the x" could be "Data tool display of mass_A of the x"
final form could look like this
Figure 3. Data tool display of mass_A of the x versus t view where a line fit equation of x = at + b is used with parameters a = 1.733 and b = −0.005 as determined using Tracker. By comparing with equation (4x), it is determined that vx = 1.733 m s−1.

Query B:
Author: Figure 9 not cited. Please check.
insert (figure 9) into the Page 5 after "Expert students can be challenged to extend their own learning to model air resistance by comparing the trajectories of the dynamic particle model and that of the real video, and being convinced that the video’s projectile motion cannot be realistically assumed to be a motion with significant air resistance (figure 9). "

please note, you may wish to reposition the actual Figure 9 nearer to the Paragraph in Page 5?

Page 8
Query 1:-
Author: Please check the details for any
journal references that do not have a blue link as
they may contain some incorrect information. Pale
purple links are used for references to arXiv eprints.
URL are provided for this with not blue link

look like this
[3] Wee L K 2010 Ejs Open Source Projectile Motion with Drag Java Applet (Open Source Physics,
Singapore, 2010) W Fendt, Projectile Motion (2002)

Query 2:-

Author: [4]: Any update?
Add URL and remove (unpublished)
[4] A. E. Prescott and M. Mitchelmore, presented at the Proceedings of the 29th Conference of the International Group for the Psychology of Mathematics Education, Melbourne: PME., 2005

Query 3:-
Author:[5]: Please check journal title.
URL is
Title: Understanding Projectile Acceleration
Journal: Journal of Experimental Psychology Human Perception and Performance
the form could look like this
H. Hecht and M. Bertamini, "Understanding Projectile Acceleration," Journal of Experimental Psychology Human Perception and Performance vol. 26, pp. 730-746, 2000.

Query 4:-
Author: [8]: Please check year given here.
[8] D. Brown. (2012). Tracker Free Video Analysis and Modeling Tool for Physics Education. Available:
Query 5:-
Author: [11]: Any more details?
It is a computer program listed in , perhaps the URL could be useful.
D. Brown, Xuggle Installers (2012).
Query 6:-
Author: [17]: Please provide publisher and
publisher =  Greenwood Publishing Group
place  = Chestnut St, Norwood, NJ, USA
final form could be
J. L. Lemke, Talking Science: Language, Learning, and Values. Chestnut St, Norwood, NJ, USA: Greenwood Publishing Group, 1990.

Query 7:-
Author: [18]: Please provide publisher name.
publisher = Falmer Press , Routledge, Taylor & Francis Group
place = Chestnut Street, Philadelphia, PA, United States:
R. T. White and R. F. Gunstone, Probing understanding. Chestnut Street, Philadelphia, PA, United States: Falmer Press, Routledge, Taylor & Francis Group, 1992

Tuesday, May 22, 2012

One-MOE Exhibition at Level 5 MESRC on 22nd May

Dear Innergy (HQ) Awards Winner,

As part of the Public Service Week 2012, we will be having a One-MOE Exhibition at Level 5 MESRC on 22nd May (Tues). Your Innergy Awards Poster will be displayed. As Moe will be visiting the exhibition, can we please request that one member of your team be present from 9.30am to about 10.45am, just to standby by your poster as some may have some questions about your project.
One-MOE Exhibition poster by MOE Ideal. Great Looking Posters and good organization of events
click this for the progress of the reasons why we are presenting Innergy Award(12)
ETD & AST Gravity-Physics by Inquiry
ETD Bringing ideas to practice

Monday, May 21, 2012

43 seconds see lookang and minister Heng receiving the gold innergyaward

43 seconds see lookang and minister Heng, receiving the gold innergy award.

Was wondering where can I find the photo :)

At 43 seconds of the video EF2012 Highlights, lookang receiving the gold innergy award from minister Heng.

Learning Journey to Google Singapore

Update 07June 2013:
@suaneu is the guy who gave one of the better talks during Technology in Education, maybe you can twitter him to ask of a visit to Google @SG.

Learning Journey to Google Singapore

Google’s creative work
An embodiment of Google’s creative work environment greets you as you walk into the office
Google signage
A Google signage at the recreational area created by the Googlers using pasta

View Larger Map
Time: 1400
Date : 25 May 2012
Venue : 8 Marina View, Asia Square 1 #30-01 Singapore 018960
Programme :
Presentation on Innovation @ Google
  • How Google grew (our philosophies, approach towards the Internet)
  • Work Culture
Technology in Education
  • Why Google cares about Education
  • Education trends and where we see things heading towards
  • Using Technology to break through socio-economic barriers
  • Technology is just a tool: How to empower teachers through technology, not replace them
  • Collaborative Environments: Relevance for Teaching, Learning, Research, or Creative Inquiry
  • Mobiles and Apps: How to utilize the next wave of technology in the classroom
Chromebook Workshop
: We will have Chromebook demo units on hand for attendees to test and explore.
  • 100% Web: Why the Web is here to stay
  • Innovation in the Cloud: How Google is disrupting technology through our Cloud initiatives
  • Chromebook classroom: How schools are using Chrome and Chromebooks to access, process and create content
  • Scalability: How you can quickly scale from 10 devices to 10,000 devices in a 1:1 computing environment
  • Ease of Management: Managing devices through a web-based console

Wednesday, May 16, 2012

My Forum Post Number 23
added a new poll in my forum, running until 2014 31 December, no prize for guessing who voted first!

interesting that i can't copy and paste out my post. maybe a firefox bug

anyway, here it is!

It might interest you to visit this
Gravity-Physics by Inquiry
it includes the write-up PDF with details in the reference section where anyone can download the 4 computer models that is has been well received by Physics educators in Singapore and in the world.
Do share this with your friends who might find the info useful :)
the 4 models are here.
ejs_EarthAndSatelite.jar (2443k) 
ejs_GField_and_Potential_1D_v3wee.jar (1494k)picture of computer model with g and V to scale of the right and data analysis tool for investigation that dV/dx = -g

ejs_innergyGFieldandPotential1Dv2EarthMoonwee.jar (2037k)

ejs_KeplerSystem3rdLaw03.jar (2782k)
my blog
please contact me if you have similar research interest on using open source physics tools for physics learning. i have a menu here of 65+ computer models free for anyone to use, download and remix.

i would like to thanks the open source physics community, namely
Paco, Andrew Duffy, Todd Timberlake for the 4 computer models where we stand on the shoulder of giants to make the world of physics learning come alive!

What evidence(s) are there of the speed of the Ferrari was traveling at140± 30 km/hr?

updated 10 july 2014: indeed the Ferrari car's black box report data was 168 km/hr matches the accelerating model A: x = 2.137E1*t^2+3.283E1*t-5.251E-2
updated with inputs on length of FERRARI car travel to be 13.0±  1 m with table of data showing 9 frames ending at time t = 0.30 s
model  accelerating model A: x = 2.137E1*t^2+3.283E1*t-5.251E-2
model constant velocity B:  x = 3.925E1*t-3.380E-1

hint for model A: model  accelerating model A: x = 2.137E1*t^2+3.283E1*t-5.251E-2

hint for model B: B:  x = 3.925E1*t-3.380E-1

Ferrari 599 GTO crashed a Taxi causing 3 dead, 2 injured in Bugis S'pore - 12May2012
updated with inputs on length of FERRARI car travel to be 13.0±  1 m with table of data showing 9 frames ending at time t = 0.30 s

updated with inputs on length of FERRARI car travel to be 13.0±  1 m instead of the older assumption of 10 m 

using Google map to locate and make sense of the actual video scene, a bit of an attempt to measure the distance on the map but the length is too small for accurate distance measurement of 10 m

Google map street view from the taxi camera position


Step1: use any YouTube down-loader such as this But this may result in a video that is frame-frame at 30, though the answer don't not change.
you can use your iOS phone to download the video in a *.mp4 which is frame-rate at 25, which some people have emailed me to ask me, but the final answer  is still the same.

Step 2: save the video into the computer

Step 3: use tracker to open the video file, recommended to install on your computer.

new estimates of length of car travel in video is now 13.0 ±  1 m , still the cab bumper can be fitted by 1.81 m length

reason for readjusting the length of car traveled, results from a discussion with physics education expert D, Wong who suggested using nokia maps
to estimate the length of car in the video ( we measure from 2 white line of the pedestrian walking to the center of the junction box. )
to estimate the length of car in the video ( we measure from 2 white line of the  pedestrian walking to the center of the junction box. ) show about 13 ±  1 m, against the map scale on the bottom right 10 m
using tracker, the measurement of length is done easily using calibration tape (length to be measured)  and stick (10m)

even after some prompting by others physics experts to use Google map to calibrate the length this is what i found.

Google map this time, again the length from 2 white line to centre of junction box is about 13 m
use tracker to measure length

Step 4 :state assumptions made:
  1. taxi camera is stationary for the duration of the 0.3 seconds the Ferrari sped across
  2. the height of the traffic light post is approximately 2.0 m from base to green light center
  3. distance traveled by car is roughly 13 ±  1  10 m and bumper of taxi is roughly 1.8 m (see diagram)
  4. the video is properly time-frame as 30 frame/seconds as default in the video data, and read correctly by tracker.
  5. the Ferrari is traveling at constant acceleration = 0 m/s^2track the front of the Ferrari.
Step 5: calibrate pixels in video with known lengths, improved strategy after discussion on Facebook distance traveled by car is roughly 13 ±  1  10 m and bumper of taxi is roughly 1.8 m.

Step 6: Make roughly 8 to 9 points as shown

Make roughly 8 to 9 points as shown
even if you use a video with a frame rate of 25, the answer is still quite the same.
notice in this video the frame rate is 25, because it is a *.mp4 taken from my iOS, the number of points is now 8 instead of 9 from frame-rate 30, making the time still 0.32 instead of 0.3

Step 7: .Analyze the speed

7.1 s vs t graph, which is roughly 39.23 m/s from as evidence from the

linear fit x = 39.231*t + -0.352 where a = 39.231 which means the average velocity assuming a constant velocity motion 

7.2 v vs t graph statistic mean v average = 39.75     30(wrong estimate)  60 (wrong estimate) m/s

data tool notice the mean for x is 3.975E1 which means 39.75, another evidence of average velocity

average it out = (39.231+39.75)/2 = 39.5 m/s

Error Analysis:

The average velocity $v_{average}$ of an object moving through a displacement $\delta d$ during a time interval $\delta t$ is described by the formula:
$v_{average}= \frac { \delta d}{ \delta t}$ 

error analysis suggests,

$ \frac{\Delta v_{average}}{v_{average}} = \frac { \Delta (\delta d)}{\delta d} +  \frac { \Delta (\delta t)}{\delta t} $ 
using estimates of 

$\Delta (\delta d)$ = 1 m (estimate from nokia map), $\delta d$= 13 (nokia map)

$\Delta (\delta t)$  = 1/30 (from framerate) , $\delta t$= 0.30 (from tracker) or

$\Delta (\delta t)$ = 1/25 (from framerate) , $\delta t$ = 0.32 (from tracker) 

v = 140 m/s 

therefore, $\Delta v $  = 0.18*v = 26 ≈  30 m/s (1 sign figure) the order of uncertainty remains ≈  30 m/s even for a frame-rate 25 video.


when converted to km/hr, v = 39.5*3600/1000 = 142 km/hr  140 ± 30 km/hr ( follow the order of magnitude of the error) 


The vehicle is likely to be traveling at speed of 140± 30 (current best estimate, as of 17May2012)  

What do you think ??

Source of errors:

  1. moving source camera and some parallax error taxi camera was not stationary for the duration of the 0.3 seconds the Ferrari sped across.
  2. the distance 13.0 m traveled by the car may not be corrected measure, thus, a Nokia map was used to check, also cross check with a Google map.
  3. the height of the traffic light post is not 2.0 m from base to green light center
  4. the source of the video could not be verified in the time frame used to capture the video, and the time-frame may not be  30 frame/seconds, though it is likely to be correct. even for 25 frame-rate for *.mp4 files, the answer for (8 pointers) t = 0.32 s would be about the same as (9 pointers) t = 0.3 s for frame-rate 30.

Physics & Science lesson learn could be:

  • Using current affairs to educate the children on everyday physics and making physics relevant.
  • using evidences to justify claim. 
  • science knowledge is socially constructed with newer evidences suggesting better ways of explaining the phenomena.

Moral lessons caught could be: 

  • Don't drive recklessly.
  • Don't beat red lights.
  • Be responsible 

Open Content Sharing of Educational resources creative commons attribution:
the video, trk files are downloadable at NTNU java Forum , available to registered users of the forum, registration is FREE.
* trackerF04.png (324.91 KB, 1280x994  )
* videoplaybackwee.trk (14.38 KB  )
* (2382.25 KB ) based on incorrect light post height
* (2594.63 KB ) based on incorrect length of car traveled in video evidences and measurements
* (2996.85 KB) based on better estimates of length of car travel 
* (2822.43 KB ) source files for frame-rate 25 video and Google satellite map analysis


This post is made with the best intentions to share good active learning practices in physics education, any offenses taken please leave a comment, i will amend the post or/and to remove offensive content if any.

The mass media media corp 5 news also reported on the accident.

there are other estimates that may interest you

other links on this post:
my ex-student T Wee's Facebook photo
SMS by ex-student T Wee, thanks!