Wakali wa Physics manasemaje juu ya hili?

Mrimi

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Habari ya mwaka mpya waungwana.
Nimekuwa nikitatizwa sana na hili jambo,naombeni wenye uelewa wanisaididie ili na wengine wenye interest ya kujua wanufaike.

Nataka kujua,ile "tochi" ya matrafiki wa barabarani inatumia principle gani kudetect speed ya gari.Je ni image ya ile moving object(gari) au change in sound frequency ya object towards an observer (ile tochi)? Au ni nini hasa?
 
Zile zinatumia image force detection, lakini tatizo zinafanya kazi kwa kiwango cha makadirio tu, haziwezi determine actual speed
Normally zinatoa matokeo below actual speed
 
C6 said:
dopler effect
Click to expand...


alphoncetz said:
Zile zinatumia image force detection, lakini tatizo zinafanya kazi kwa kiwango cha makadirio tu, haziwezi determine actual speed
Normally zinatoa matokeo below actual speed
Click to expand...

Hapa ndipo ninazidi kuchanganyikiwa,au wenzangu nyie mnaonaje? Image au change in sound freq.(doppler effect)?
Hivi kwanza kale kakitu kanaitwaje kitalamu,ili tujaribu hata kugoogle basi!
 
Ile tochi inapima relative speed. Anapoielekeza kwako halafu kwa mfano wewe ukawa kwenye speed 100km/hr tuna-asume ile tochi iko stationary hivyo speed yake ni zero i.e 0km/hr hivyo inachofanya ile tochi inatafuta relative speed kwa kutoa negative ya speed yako yaani 0km/hr-(-100km/hr)=100km/hr.

Lakini kwa sababu wale maaskari huwa wanaificha ile tochi na kuielekeza kwako ghafla hicho kitendo kinafanya hiyo tochi nayo iwe kwenye speed labda tuseme 5km/hr hivyo kama speed limit ilitakiwa iwe 100km/hr akikuelekezea kwako ukawa kwenye speed 100km/hr anakuwa amepata relative speed ya 5km/hr-(-100km/hr)=105km/hr kwa hiyo unakuwa ume-over speed!
 

Kwa hiyo inatumia principle ipi kati ya hizo zilizotajwa hapo juu?
 
Inapima speed ya gari kwa kupima muda unaochukua mwanga kutoka kwenye "tochi" kufika kwenye gari, kuakisiwa "reflected" na kurudi tena kwenye "tochi"

Kwa kugawa muda huo uliopatikana kwa mbili na kwa vile kasi ya mwanga inajuulikana, basi distance iliyopo gari kutoka "tochi" inaweza kujuulikana.

Kwa vile mwanga unakasi kubwa, ndani ya sekunde unaweza kujua mabadiliko ya distance ya gari kulinganisha na ilipo tochi.

Ukiweza kujua mabadiliko ya distance ya gari with time ndio umeshajua kasi ya gari hiyo

Kwa hiyo in short inachopima ni mabadiliko ya muda utakaohitajika kureflact mwanga kutoka kwenye tochi hadi gari ili kujua mwendo kasi wa gari hiyo
 
Brother Kinyungu hapo hapo kwenye 105 kwa nini isiwe 100 - 5 = 95km/hr?
 

OK. Kwa hiyo hii ni kusema kwamba,ni lazima object(gari)iwe visible,sio? So,kama kuna kona au any obstacle in between inakuwa haifanyi kazi. Hapo nimekuelewa kwa kiasi fulani.Juzi nilikuta watu wanaongea kwamba ukiweka CD hizi za kawaida kwenye kioo cha mbele cha gari,ule upande wa CD inaong'aa sana u-face kwa mbele(walipo matrafiki) inazuia ile tochi kufanya kazi.Sikuchangia chochote, by the way sikujua ile tochi inafanyake kazi.

Vipi sasa,kitalamu hii kitu inaitwaje?!
 

Ndio, ni mpaka tochi ielekezwe kwenye gari husika na lazima mwanga wa tochi uweze kuifikia gari.

Kimsingi CD hazitakuwa na athari yoyote licha ya kuwa zitakuwa zina reflect mwanga wa jua (nakisia kuwa umekusudia matumizi ya mchana) kwa sababu mwanga unaopimwa muda na tochi ni mwanga uliotolewa na tochi sio mwanga kutoka source nyengine

Juu ya hivyo, hakikisha unajifunza sheria za barabarani za nchi uliyopo kwa sababu kwa nchi nyengine kuning'iniza CD au kuweka CD au any other reflective surface kwenye/ karibu na kioo cha mbele/nyuma cha gari yako ni kinyume na sheria za usalama wa barabarani
 
Kwa ufupi hii torch ina work using the Doppler's effect!

Practical Applications of the Doppler Effect

In the 160 years or so since Doppler first described the wave phenomenon that would cement his place in history, several practical applications of the Doppler effect have emerged to serve society. In all of these applications, the same basic thing is happening: A stationary transmitter shoots waves at a moving object. The waves hit the object and bounce back. The transmitter (now a receiver) detects the frequency of the returned waves. Based on the amount of the Doppler shift, the speed of the object can be determined. Let's look at a few specific examples.


Police Radar
The handheld radar guns used by police to check for speeding vehicles rely on the Doppler effect. Here's how they work:





  1. A police officer takes a position on the side of the road.
  2. The officer aims his radar gun at an approaching vehicle. The gun sends out a burst of radio waves at a particular frequency.
  3. The radio waves strike the vehicle and bounce back toward the radar gun.
  4. The radar gun measures the frequency of the returning waves. Because the car is moving toward the gun, the frequency of the returning waves will be higher than the frequency of the waves initially transmitted by the gun. The faster the car's speed, the higher the frequency of the returning wave.
  5. The difference between the emitted frequency and the reflected frequency is used to determine the speed of the vehicle. A computer inside the gun performs the calculation instantly and displays a speed to the officer.
 
Habari ya Mwaka Mpya wana JF,

Ukweli ni kwamba ile tochi inafanya kazi kwa kupima msukumo wa mawimbi waves compression.

gari linapokua kwenye speed lina sukuma upepo au mawimbi ya upepo kadri gari linapokua na speed kubwa kompression huongezeka so inasoma msukumo ule na kudetermine speed ya gari na wala sio picha au image kama walivyo sema wenzangu na ndio maana hawawezi hata kujua namba ya gari iliyo over speed.

Stay blessed wana JF
 
Never give up said:
kitaalamu inaitwaje? maana imezoekeka tu jina ya torch.
Click to expand...

Wataalamu watuambie kama ni hii:

LIDAR (Light Detection And Ranging, also LADAR) is an optical remote sensing technology that can measure the distance to, or other properties of, targets by illuminating the target with laser light and analyzing the backscattered light
 
.....Siku hizi Traffic wanaagiza wenyewe zile Torch ,hata hatujui kwa nini wanaingia gharama kubwa vile ili kila mtu awe na ya kwake...au ndio mradi huo?kabla utaratibu uilikuwa zinanunuliwa na wadau au hata na serikali......la hasha siku hizi wanaagiza wenyewe kwa suppliers..itajilipa ndani kwa ndani!
 
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