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,
CLICK the mouse button to stop your car.

You reaction time will determine if an accident will happen or not.
(and how many cars will be involved in the incident)

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.

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
                                     ray@middx.screaming.net

Your suggestions are highly appreciated! Please click hwang@phy03.phy.ntnu.edu.tw

Author : Fu-Kwun Hwang, Dept. of physics, National Taiwan Normal University