Por a sintix experiment. yon woulkl lbke to use the Doppler effect to doubie the
ID: 1794088 • Letter: P
Question
Por a sintix experiment. yon woulkl lbke to use the Doppler effect to doubie the pencuived fresr ofi·harmooicn, frota the 267112 trtse (middle C) that lt emits, to 5233 lls (C5inte). tri (a) Which stratesy will accompliats yuur goal mure eusily: move the harnonica on mave the obrvert (b) Caleulate the speed of the harmoniea must have in order for a stationary obeerver to heat 523 3 Hx. (1.0 pointa) the, 8pold an observer most have in order to persive 523.3 Hz oound from stationary harmonica that emits eound at 261.7 Ha. (1.0 points) (d) A firetruck moves cast at a speed of 33.5 m/s, the siren is emitted at a frequenty of 400 Hla. hat frequency ls heard by a person in a car travelling west at 24.6 m/s as the car spprosch the firetruck? (1.0 points) (e) What frequency is heard by the person in a car travelling weet at 24.6 m/'s as the car imaves away from the firetruck? (1.0 points) (f) What is the change is frequeney detected by the person in the car? How nsch perentage of the true frequeney? (1.0 points) (g) II the car is parked on the side of the highway as the firetruck speeds by? What frequency does the person in the car hear as the ambulance (a) approaches (b) and recedes? (1.0 points)Explanation / Answer
a) Both can be done to acheive what we required.
b)
f' = f*v_sound/(v_sound + v_harminic)
523.3 = 561.7*343/(343 + v_harmonic)
==> v_harmonic = 25.1 m/s
c) f' = f*(v_sound - v_oberver)/v_sound
523.3 = 561.7*(343 - v_observor)/343
==> v_oberver = 23.4 m/s
d) f' = f*(v_sound + v_observor)/(v_sound - v_source)
= 400*(343 + 24.6)/(343 - 33.5)
= 475 Hz
e)
f' = f*(v_sound - v_observor)/(v_sound + v_source)
= 400*(343 - 24.6)/(343 + 33.5)
= 338 Hz
f) delta_f = (475 - 338)
= 137 hz
delta_f/f = 137/400
= 0.342
= 34.2 %