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JDK1.0.2 simulations (1996-2001) => kinematics => Topic started by: Fu-Kwun Hwang on January 29, 2004, 08:53:19 am

Title: Reaction time and car accident
Post by: Fu-Kwun Hwang on January 29, 2004, 08:53:19 am
If you want to measure your personal reaction time, please check out Reaction time

This applet try to demonstrate how your reaction time related to car accident. May be you prevent the car accident, but those car behind you might have car accident due to your slower response.

There are 10 cars in a row, all moving in the the same direction with  the same speed.

You are the  driver of the second car.

    When the first car brakes, its color will turn from yellow to red,

    (left)CLICK the mouse button to stop your car.

The average reaction time for the other drivers is control by the value of the T= field_value + 0.1 *random seconds.

The default is 0.5 s which means the reaction time for all the drivers are between 0.5 and 0.6s

You reaction time will determine if an accident will happen or not.

(and how many cars will be involved in the incident)

move mouse cursor inside simulation region,
click left mouse button when the color of the first car turn red

    You can enter different speed with selected unit.( m/s, km/hr, mi/hr)

    distances d between cars and

    the friction coefficient of the tire and the road. (0.8 will be a good value for normal situation)

    The graph show the velocity for all the cars.

    If the car turn red, you know what happened to it.

Subject: Reaction time & car accident
Date: Sun, 24 Oct 1999 21:00:03 +0100
From: "Ray Holloway" middx@middx.screaming.net
To: hwang@phy.ntnu.edu.tw

I have only just found your wonderful web-site & have tried the
accident experiment, it really is a good lesson for us drivers.Perhaps it should be included in driving tests.
I had not appreciated the "knock on" effect until I noticed that although I could stop in time those behind me could not.
I found that at 100 mph I had to allow 75 feet between cars for them
all to stop & even then it was not succesful every time. A wet road would of made it much worse.
Thanks for a very interesting site, although I have no formal education
in Physics I find it fascinating, so I am going to try the other experiments now.
Regards, Ray Holloway


Title: ?
Post by: on February 19, 2004, 02:17:48 am
It appears that t cannot be adjusted, as vehicles 3-10 all react at a half second despite assigning a new t.

Title: topic138
Post by: Fu-Kwun Hwang on February 26, 2004, 08:05:11 am
I believe you forgot to hit [enter]  after you  provide new value in the textfield.
The program need to know when you finish enter value.
However, I change the program so that when you hit reset it will read new value.
So it should work now (even you forget hit [enter]).

Title: Downloading the Reaction time and car accident applet.
Post by: rfortescue on May 16, 2005, 01:13:42 am
Hi Hwang,

I have tried to download the applet so that I can use it for demonstartions in class using a computer that is not networked.  I have not received the applet, however!

I received the Reaction Time Measurement applet OK.

Can you help?

Title: topic138
Post by: Fu-Kwun Hwang on May 16, 2005, 07:37:44 am
If there is an error when send out the email and file, our server should have displayed error message on your web page.
Please try it again. If you still did not receive it, please provide me your email address. I can send it manually.

Title: reaction time
Post by: prajakta on September 04, 2005, 07:13:27 pm
dear sir/madam,

this mail is in regards to the driving accident test. i am an electronics engineering student and we are doing a project based on reaction time. in this a person will see a stimulus and depending upon that will have to press a key.it will be simple as well as choice reaction time(SRT AND CRT). i found the driving accident test similar to our project.
      i kindly request you to give me some information regarding this.also some applcations of reaction time measurement.


Title: topic138
Post by: Fu-Kwun Hwang on September 05, 2005, 07:20:19 am
You can check out the following URL for reaction time measurement (http://www.phy.ntnu.edu.tw/ntnujava/viewtopic.php?t=224)

Title: topic138
Post by: Fu-Kwun Hwang on April 19, 2006, 01:15:49 pm
Someone send me video which shown  car accident (http://www.phy.ntnu.edu.tw/demolab/phpBB/pics/lefortovo.wmv) happened inside a tunnel in Russia.

Title: topic138
Post by: green8003 on April 26, 2006, 04:54:09 pm
im a new member and i dont know that how i dowload the simulations.
if anyone help me this subject i will be glad

Title: topic138
Post by: rhipple on April 26, 2006, 08:24:42 pm
You have to click the "get applet files" button near the simulation. Then the files will be mailed to you. I think you have to ask Dr. Hwang directly for the source, however.

Title: topic138
Post by: green8003 on April 27, 2006, 11:23:26 pm
thanks rhipple
but i didnt see the thing that you say me.where is that?
im apologise for this

Title: topic138
Post by: rhipple on April 28, 2006, 12:56:06 am
Here is an example. Go to
 NTNU JAVA -> Physics simulations -> kinematics
and look for "bouncing ball". Go to that simulation.
Scroll down and you will see the GET APPLET FILES button. You'll find it after the explanatory text. It should be emailed but sometimes not immediately.

Title: topic138
Post by: green8003 on April 28, 2006, 03:39:23 am
again tahanks rhipple
i found and did. :)

Title: congratulations and sorry for my english
Post by: Edu on June 09, 2006, 08:11:54 pm
just entered the site and im amazed, specially with the time reaction and car accident applet. it is great and makes me think not only about physics, but about how we drive some times.

i would be very interested in showing the applet to my studients. is it possible to download it? i tried to find it but i couldnt. i have already downloaded the time reaction applet with the trafic light turning on red, but i would like to have the accident one to complete the practical utility of it

thankyou in advance for your help, and congratulations once again

Title: topic138
Post by: Fu-Kwun Hwang on June 12, 2006, 08:22:53 am
Please check out the first message!

Title: Re: Reaction time and car accident
Post by: brokenjay on January 25, 2010, 11:32:41 am
We just need to know that in the applet, some car accident, which has a 50% chance of happening, could cost the person his entire net worth. Then, everyone cares their car insurance for the better aspect. I think that it could be done to the process of facing extra risk.

Title: Re: Reaction time and car accident
Post by: kidashley25 on June 19, 2010, 03:25:21 pm
Hard to get in a fatal accident doing 25 in a 45 with your blinker on. It's better for you to drive home drunk than walk home drunk.

Title: Re: Reaction time and car accident
Post by: josevalle on January 15, 2020, 09:58:40 pm
Beautiful info, guys!