It's been a while I haven't give Physics lesson. In interference, you learnt the wavelength = ax/D formula. Now, let's have some fun regarding the sound wave experiment interference, as shown in diagram below:
You can see the relationship between the distance between two coherent speakers, a (dog) and the distance between two loud sound heard, x (cat). That's because they are inversely proportional (cat & dog always fight!). But your teacher can easily teach their relationship via the formula itself.
|Af!Af! (barking sound) VS Xssss! (cat hissing)|
First, let's see the variables (simplified):
MV: a (you change the distance between speakers)
RV: x (you measure the distance between two loud sound)
CV: D (you maintain the distance between you and the speakers).
Hence, we arrive at the hypothesis (simplified):
"The larger the a, the smaller the x."
The teachers can show this as the advance organizer (from Ausubel) before the experiment starts. For the rest of you guys, have fun! :-)
Gong Xi Fa Chai! 新年快樂.