# Change in medium and its effect on sound

1. Sep 2, 2015

### faiziqb12

my question is just that how does the wavelength and frequency of sound wave change when it travels from rarer to a denser medium ...................................
and whatever is your solution please give a briefer insight into it..

NOTE:
i was recently going through a physics olympiad paper and i found from a question that when the above type of transition occurs ; from rarer to denser medium , the wavelength of the sound wave increases..

2. Sep 2, 2015

### insightful

What happens to the speed of sound in a denser medium?

What equation relates speed, frequency, and wavelength?

3. Sep 2, 2015

### faiziqb12

the speed of sound increases.....................
but does it increase due to an increase in frequency or wavelength and how?

4. Sep 3, 2015

### haruspex

How would it be possible for the frequency to change?

5. Sep 3, 2015

### faiziqb12

yes , you are right
the frequency doesnt change for a given enegy input in diffrent media....................
so it must be the wavelenth that causes the increase in speed in denser media...........

6. Sep 3, 2015

### insightful

I think of it the other way around. Consider a line of people at an airport with a "people-mover" (horizontal conveyor). On the floor, they pass you at a frequency of 1/s, and all walk at 1m/s. They step on the conveyor, which moves at 1m/s relative to the floor, while maintaining their 1m/s relative to the conveyor. You stand stationary on the floor next to the conveyor. What is their speed? What is their frequency? What is their "wavelength" (spacing)? Think about it.