Себетіңіз босСатып алу
Let's use musical instruments and our vocal cords as sources of sound.
How can this pendulum accurately measure time in seconds?
This lesson presents timekeeping devices and the types and units...
Experience the relationship between pitch and frequency through...
Objects denser than water sink in water.
Let's make musical instruments.
In this lesson you will learn more about how sound propagates.
When does echo form? Why does sound spread easier at night? What...