The point of my comment is that there is no more kinetic energy available per car in the two car head on collision than there is in the one-car into-the-wall collision. Some respondents have felt that because the relative speed of the two cars in 150MPH the energy available should be: 1/2 * M * 150 * 150 = 11250 M Instead of: 2 * 1/2 * M * 75 * 75 = 5625 M This is fallacious thinking. Bob Ammemran RAm Systems ----- Original Message ----- From: "Eoin Ross" To: Sent: Thursday, November 08, 2001 7:23 AM Subject: Re: [ot]: how does a radar detector work? >> Again, where does this energy come from? If you can tell me, I'd like to go >> into business with you selling perpetual motion machines. >> Bob Ammerman >> RAm Systems Its High School Physics ......... Crater size is related to the mass(m) and velocity(v) of the impacting body. These two quantities can be combined to find the kinetic energy of an impactor, defined as K = = m v2 where K is the kinetic energy, m is the mass of the impacting body, and v is the velocity of the impactor. Review the results of your crater experiments in section IIA. The size of the crater increased with the mass of the bolide, and also with the height from which it was dropped (which is proportional to the speed of impact). This fundamental physical relationship allows an estimate of bolide mass to be made from crater diameter. The energy comes from the fuel you burn in acceleration of the mass to it's velocity, The energy expended to keep it moving is to counteract the effects of friction and drag. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics