I did a lab in which we were to find the 1st resonance and 2nd resonance and from them we found wavelength which in turn helped us find speed of sound. We used tuning forks and the frequancy was given. We besically moved a plastic tube which was in water up along with he tuning fork (in air) until resonance was heard.

Question

I did a lab in which we were to find the 1st resonance and 2nd resonance and from them we found wavelength which in turn helped us find speed of sound. We used tuning forks and the frequancy was given. We besically moved a plastic tube which was in water up along with he tuning fork (in air) until resonance was heard.

Question:
1. Sound travels faster in water than air. In the experiment, which aspects of wavelength, speed of sound and frequancy changed when part of sound travelled through water?

(my question: when did a part of sound travel through water?)

2. If speed of sound in water is faster by a factor of 4 how much did the wave length and frequancy change?

(my answer: after I answer the first question I'll figure out whether frequancy and wavelength actually do change when mediums are changed and if so I'll multiply by 4. Is this correct?)

Answer 1

1. In the mentioned experiment, only part of the sound traveled through water when the plastic tube was being moved up along with the tuning fork. When the tube was in the water, the sound waves traveled through both the water and air simultaneously.

2. To understand how the wavelength and frequency change when the medium is changed, we can consider the relationship between the speed of sound, wavelength, and frequency. The equation that relates them is:

speed of sound = wavelength x frequency

When the medium changes, such as from air to water, the speed of sound will change. In this case, sound travels faster in water than in air. Therefore, if the speed of sound in water is faster by a factor of 4, we can say that it is four times the speed of sound in air.

Now, let's assume that the frequency remains constant. Using the equation mentioned above, we can rearrange it to solve for wavelength:

wavelength = speed of sound / frequency

If the speed of sound in water is four times faster than in air, we can substitute the values:

wavelength in water = (4 x speed of sound in air) / frequency

Hence, the wavelength in water would be four times shorter than the wavelength in air, assuming the frequency remains constant.

To recap, the frequency does not change when the medium changes, but the wavelength changes proportionally to the difference in the speeds of sound in the two mediums.