An opera singer in a convertible sings a note at 600 Hz while cruising down the highway at 90km/hr. What is the frequency heard by a person standing beside the road in front of the car?

Explanation:

Given data

Frequency fs=600 Hz

Velocity Vs=90 km/hr =25 m/s

Speed of sound v=343 m/s

To find

Frequency f heard by a person standing beside the road in front of the car

Solution

From Doppler's effect we know that:

Here Vs is negative as the source is moving towards listener

layers of the earth affect the waves and these effects are seen on instruiments such as seimometers