Section: Chemical and Physical Foundations of Biological Systems

40) A source emits a sound from one medium with a certain velocity, intensity, frequency and wavelength. When the sound exits the first medium and enters a denser medium, all of the following changes EXCEPT:

1. velocity
2. intensity
3. frequency
4. wavelength

This question is testing your understanding of the properties of sound as waves travel from one medium to another. To answer this question, you must know that the frequency of sound and light always remains constant when changing mediums. The wavelength on the other hand does change, and a change in the wavelength causes a proportional change in the velocity since v = ?f. Intensity is also proportional to velocity and so A, B, and D are all incorrect. Thus, C is the correct answer.