# NTNUJAVA Virtual Physics LaboratoryEnjoy the fun of physics with simulations! Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

## Information about this web site => Request for physics Simulations => Topic started by: finnlysell on February 24, 2008, 04:44:39 am

 Title: Speeding applet Post by: finnlysell on February 24, 2008, 04:44:39 am I would like to have an applet that shows the consequenses of speeding. In Urban area it is only allowed to have a speed of 50 km/h.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/hThe 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 secI hope that somebody would like to do the applet.Best wishesFinn LysellDenmark Title: Re: Speeding applet Post by: Fu-Kwun Hwang on February 24, 2008, 03:52:25 pm I hope the following applet is what you want.There are two cars in this simulation.Those two cars have the same initial conditions.When radio button labeled "all" is checked: (default state when "initialize" button is clicked). You can adjust initial velocity, reaction time and friction coefficient for both cars with sliders.If you radio button "2" is checked: The sliders only change values for car number 2.Both cars will move from left to right after you click "play" button.The simulation assume at a random time (selected by random number), both driver saw something bad happened and s/he will stars to hit the brake and stop the car (However, the reaction time and stopping are controlled by adjustable slider(reaction time/friction coef.) before you click play button. The V-t diagram will save the last three sets of v-t traces so different conditions can be compares.Let me know if you need more features!