What evidence(s) are there of the speed of Ferrari was traveling at 216 km/hr?
Using Tracker physics comes alive and becomes relevant to everyday life

made a post here
http://weelookang.blogspot.com/2012/05/what-evidence-of-speed-ferrari-was.html

sharing the source trk and video here




Ferrari 599 GTO crashed a Taxi causing 3 dead, 2 injured in Bugis S'pore - 12May2012






video analysis using tracker on Ferrari & taxi crash at Bugis Rochor Junction dated







using a video found here
http://www.youtube.com/watch?v=S80bDrxrCiI&feature=related








Step1: use any YouTube down-loader such as this
http://downloadyoutubevideo.org/download.php?url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DS80bDrxrCiI%26feature%3Drelated



Step 2: save the video into the computer



Step 3: use tracker http://www.cabrillo.edu/~dbrown/tracker/ to open the video file





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. the video is properly time-frame as 30 frame/seconds as default in the video data, and read correctly by tracker.

  4. the Ferrari is traveling at constant acceleration = 0 m/s^2

    track the front of the Ferrari.






Step 5: Make roughly 8 to 9 points as shown








using tracker to trace the motion of the car



Step 6: .Analyze the speed





which is roughly 60 m/s from as evidence from the



6.1 s vs t graph,






linear fit x = 60.178*t + -13.821 where a = 60.178 which means the average velocity assuming a constant velocity motion







linear fit x = 60.178*t + -13.821
by comparing coefficient to constant acceleration equation x = u*t + x0
roughly u = 60 m/s





6.2 v vs t graph
statistic mean
v average = 60 m/s








data tool notice the mean for x is 6.097E1 which means 60.97, another evidence of average velocity











Conclusion:



when converted to km/hr,
v = 60*3600/1000 = 216 km/hr = 210 km/hr ( round down 2 significant figures) = 200 km/hr ( 1 significant figure).



Claim:

The vehicle is likely to be traveling at speed of 200 km/hr, given the evidences and assumptions made in the analysis.




Question:

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 height of the traffic light post is not 2.0 m from base to green light center

  3. 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.




Physics & Science lesson learn could be:






Morale lessons caught could be:  




Disclaimer:

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.