Concepts 2

Question 1

Pitch of sound when source moving away from observer or detector

Answer 1

If source is constantly moving away from observer, successive wave crests would take longer to reach observer
It will perceive lower pitch
The faster it moving away, the lower the perceived pitch would be

Question 2

Question with moving bat that emits sound waves towards stationary wall

Answer 2

Because bat is moving to wall, distance between wall and batt decreases, but bat will emitt the same number of waves or waves of same wavelength. Therefore, bat intercept more wavelength per second than it would intercept if it were stationary. Since frequency is the number of wavelength per second, more wavelength mean a higher frequency.

Question 3

Wave goes from one medium to another

Answer 3

When wave goes from one medium to the other, it’s speed and wavelength might change but it’s frequency will remain constant

Question 4

Rule of thumb for decibels

Answer 4

For every increase of 10 dB, the sound is 10 times more intense