Question

Two trains are traveling on the same track in the same direction. The whistles of both trains produce a 440Hz frequency sound. The lead train is traveling at 120km/hr. Both trains blow their whistles. The driver of the lead train hears that the following train has a higher frequency sound. She also notices an oscillation of 4.0 Hz.

A.) How do you explain the higher frequency sound heard by the lead train driver?

B.) How do you explain the 4.0Hz oscillation?

C.) What is the speed of the following train?

D.) The trains are 500m apart, should the lead train driver be concerned? Why or why not?

Answer #1

Data Given

Frequency

Speed of lead train v_{1} = 120 km/hr = 33.33 m/s

Let speed of the following train = v_{2}

Part A) The higher frequency sound heard by lead train driver is due to Doppler effect and it is due to the observer and source motion.

Part B) 4 Hz oscillation must be due to because the following train is moving faster than the lead train.

Part C) Let us consider the relative speed of the trains is v

As v is the relative speed i.e.

Part D) Yes the lead train driver must accelerate to avoid the collision.

A girl is standing at a railroad crossing for a track that runs
east and west. As she faces the track, east is to her right and
west is to her left. Two trains on the track some distance apart
are headed west, both at speeds of 7.20 m/s, and blowing their
whistles (which have the same frequency). One train is approaching
her from the east and the other is traveling away from her toward
the west. (Assume the speed...

Two trains emit 445 Hz whistles. One train is stationary. The
conductor on the stationary train hears a 3.1 Hz beat frequency
when the other train approaches. What is the speed of the moving
train?

Two trains are traveling toward each other. One train is
traveling at 31 [m/sec] from our left to the right. The other train
is traveling at 40 [m/sec] from the right to the left. The train on
the left blows the whistle at fο = 520 [Hz]. a) What is the
frequency heard on the other train in still air? b) What is the
frequency heard on the other train if there is wind blowing from
the right to the...

A train on one track moves in the same direction as a second
train on the adjacent track. The first train, which is ahead of the
second train and moves with a speed of 36.4 m/s , blows a horn
whose frequency is 125 Hz . If the frequency heard on the second
train is 134 Hz , what is its speed?

A freight train is traveling at 30.0 m/s relative to the ground
in still air. The temperature is 20° C. The frequency of the note
emitted by the train whistle is 262 Hz. A car passes by the train
on a road right next to the train track.
(a) What frequency f1 is heard by a driver of
a car moving at 18.0 m/s relative to the ground in a direction
opposite to the train and approaching it?
(b) What...

An ambulance driver traveling at 34.0 m/s (76.1 mph) honks his
horn as he sees a motorist ahead on the highway traveling in the
same direction. The motorist hears a frequency of 378 Hz and
notices that his own speedometer reads 33.6 mph (15.0 m/s).
Calculate the frequency that the ambulance driver hears. (Speed of
sound is 340 m/s) (in Hz) A: 1.17×10^2 B: 1.46×10^2 C: 1.82×10^2 D:
2.28×10^2 E: 2.85×10^2 F: 3.56×10^2 G: 4.45×10^2 H: 5.56×10^2

Two waves traveling on a string in the same direction both have
a frequency of 100 Hz, a wavelength of 2 cm, and an amplitude of
0.02 m. What is the amplitude of the resultant wave if the original
waves differ in phase by each of the following values?
(a) π/6 cm
(b) π/3

Two waves traveling on a string in the same direction both have
a frequency of 269 Hz, a wavelength of 0.29 m,
and an amplitude of 0.44 m. What is the amplitude of the
resultant wave if the original waves differ in phase by π/3
rad?
Tries 0/10
What is the phase difference between the two waves if the
amplitude of the resultant wave is 0.22 m?

Short Answers Conceptual Questions
1. (a) A lead cylinder floats in mercury at 0oC. Will the lead
float higher or lower if the temperature is raised? (b) Freezing a
can of soda will cause its bottom and top to bulge so badly that
the can will not stand up. What has happened?
2. (a) Is it possible to boil water at room temperature (20oC)
without heating it? Explain. (b) Explain why burns caused by steam
at 100oC on the skin...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 8 minutes ago

asked 24 minutes ago

asked 32 minutes ago

asked 32 minutes ago

asked 34 minutes ago

asked 46 minutes ago

asked 51 minutes ago

asked 53 minutes ago

asked 53 minutes ago

asked 53 minutes ago

asked 1 hour ago

asked 1 hour ago