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Hearing the siren of an approaching fire truck, you pull over to the side of the road and stop. As the truck approaches, you hear a tone of
Question
Hearing the siren of an approaching fire truck, you pull over to the side of the road and stop. As the truck approaches, you hear a tone of 470 Hz ; as the truck recedes, you hear a tone of 400 Hz .Howmuch time will it take for the truck to get from your position to the fire 5.0 km away, assuming it maintainsa constant speed?
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Physics
3 years
2021-08-28T17:34:58+00:00
2021-08-28T17:34:58+00:00 1 Answers
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Answers ( )
Answer:
time = 182.68 s
Explanation:
given data
truck approaches = 470 Hz
truck recedes = 400 Hz
position away = 5.0 km
solution
if V is the speed of sound in air and v is the speed to truck
f is the frequency of sound
when truck approach
f1 =
and when truck recede
f2 =
so here we can say
v = 27.37 m/s
so here 5 km
S = u×t + 0.5 ×a×t² ………..2
5 × 10³ = 27.37 t + 0
t = 182.68 s