Question

Two eagles fly directly toward one another, the first at 15.0 m/s and the second at 20.0 m/s. Both screech, the first one emitting a frequency of 3200 Hz and the second one emitting a frequency of 3800 Hz. What frequencies do they receive if the speed of sound is 330 m/s?

a) 3220 Hz, 3780 Hz
b) 3180 Hz, 3820 Hz
c) 3100 Hz, 3880 Hz
d) 3260 Hz, 3720 Hz

Answer 1

Using the Doppler Effect formula, the first eagle hears a frequency, The first eagle hears 3220 Hz and the second eagle hears 3820 Hz.

Step-by-step explanation:

When two eagles are flying directly toward one another, the frequency of the sound they hear will be affected by the Doppler effect. The Doppler effect causes a change in frequency due to the relative motion between the source of the sound and the observer. The formula to calculate the frequency is:

f' = f ((v + v_0)/(v - v_s))

where f' is the observed frequency, f is the emitted frequency, v is the velocity of sound, v_0 is the velocity of the observer, and v_s is the velocity of the source. In this case, since the eagles are flying towards each other, their velocities have opposite signs. Let's calculate the frequencies they hear:

The first eagle hears:

f' = 3200 * ((330 + 15)/(330 - (-15)))

f' = 3220 Hz

The second eagle hears:

f' = 3800 * ((330 + (-20))/(330 - 20))

f' = 3820 Hz

Therefore, the correct answer is option b) 3220 Hz, 3820 Hz.