Chuck Yeager finally breaks the sound barrier while piloting an aircraft. The people on the ground initially believe that the sonic boom was Chuck crashing but soon realize that Chuck was successful in his attempt to break the sound barrier.
Beakman explains amplification and how sound is generated. He mentions that certain sounds are louder than others due to the amount of air they disturb. They conduct an experiment to demonstrate this concept.
Phil demonstrates how to see sound in action using plastic wrap, a bowl, and table salt. The salt moves around the plastic wrap in response to the sound waves. Phil then maxes out the experiment using a Chladni Plate and sand, and he shows how sand makes different shapes based on the frequently that is emitted.
Ms. Frizzle and her class learn about vibrations and sound by playing with instruments and hitting objects. They not only hear and feel sound but see it using special glasses. Among many other lessons, they learn that high sounds are created by a fast vibration and low sounds are created by a slow vibration.