Archived posting to the Leica Users Group, 2008/11/03
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]yes.. it makes great sense. The vector of velocity coming at YOU is decreasing (if the bomb is not falling on you). thanks. Eric PS. Lightroom is DA bomb. On Mon, Nov 3, 2008 at 3:03 PM, Henning Wulff <henningw@archiphoto.com> wrote: >> thanks to all. >> >> I figured it was doppler based, but I would think the pitch would >> INCREASE as the bomb falls toward you. >> I am basing this on the increased pitch of car siren coming toward you. >> OR or as a different concept, a standing wave in an organ pipe as you >> shorten it, the pitch increases. >> >> Could the drop in pitch be related to change in air density through >> which the falling object passes? >> >> Comp sci is computer science. But in the 80's we were programming in >> LISP and Pascal.. >> So that is worth 3 cents in today's market. >> My dad used to reminisce about programing by punch cards. >> >> Eric >> > > > If a bomb is descending at its terminal velocity when you start hearing it, > and it is not aimed dead at you, the pitch will (hopefully) decrease to the > vectors involved. > > Imagine the bomb coming straight down at you (run!!!! :-)), and then one > coming straight down a couple of hundred yards away. As the one further > away > gets closer to the ground, the vector of the sound heading your way > decrease > in value. What that means is that its speed of approach (to you) is > decreasing, and just as it hits its speed of approach to you is 0. > Therefore > at the time of impact the doppler compression that the sound waves > experience is zero, whereas the sound of the bomb that is heading right at > you does not change its rate of approach to you, and you will hear the same > pitch until impact. > > > -- > * Henning J. Wulff > /|\ Wulff Photography & Design > /###\ mailto:henningw@archiphoto.com > |[ ]| http://www.archiphoto.com > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >