Xref: utzoo comp.dcom.modems:3932 sci.physics:8360
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!ncifcrf!toms
From: toms@ncifcrf.gov (Tom Schneider)
Newsgroups: comp.dcom.modems,sci.physics
Subject: Re: TrailBlazer Plus vs. lightning
Summary: divide by 5 for distance
Message-ID: <921@fcs280s.ncifcrf.gov>
Date: 31 May 89 18:36:34 GMT
References: <3784@phri.UUCP> <7994@galbp.LBP.HARRIS.COM>
Reply-To: toms@ncifcrf.gov (Tom Schneider)
Organization: NCI Supercomputer Center, Frederick, MD
Lines: 13

In article <7994@galbp.LBP.HARRIS.COM> mhw@wittsend.UUCP (Michael H. Warfield)
writes:
>storm in the area.  Lightening strikes were occuring in the 5 to 10 mile
>range by timing the thunder (you know count the seconds and divide by 6).

At sea level the speed of sound in air is 1116.45 ft/sec.
Dividing by 5280 ft/mile gives the conversion factor (1/4.73) mi/sec.
So a better rule is to divide the seconds by 5 to get the distance in miles.
  Tom Schneider
  National Cancer Institute
  Laboratory of Mathematical Biology
  Frederick, Maryland  21701-1013
  toms@ncifcrf.gov