Let us assume that a child steps into the street and that a car just manages to stop with a margin of 0,5 meter from the child ( reaction time set to 1,5 sec. and decelleration set to -0,8 m/s2 )

An other car speeding with just 10 km/h - driving 60 km/h - what will the impact speed on the child be.

In Denmark where I teach physics - the local - safe-driving organisation has had a campaign about this with advertising on buses etc. saying 10 km/h = 44 km/h

The math behind this is not very hard - but I would like to show it in an applet anyway -

You could expand problems by saying that it is slippery a=-0,4 m/s2 or you are disturbed by a phonecall - reactiontime set to 2.5 sec

I hope that somebody would like to do the applet.

Best wishes

Finn Lysell

Denmark