What puts the BOOM in fireworks? Chapter 4 Lesson one: What is Sound Energy?

Fireworks are seen before they are heard because the speed of light is much faster than the speed of sound. While the speed of light is 300,000,000 meters per second, the speed of sound in dry air is only about 343 meters per second. So, if fireworks explode 1,000 meters away, it will only take three millionths of a second for the light to reach the viewer. However, the loud boom will take about three seconds. When fireworks explode, chemical energy is released quickly as light energy, sound energy, and heat. The quick release of energy into the air around the explosion makes the surrounding air expand faster than the speed of sound. This produces a shock wave of sound energy you hear as the “BOOM.” Fireworks are seen before they are heard because the speed of light is much faster than the speed of sound. While the speed of light is 300,000,000 meters per second, the speed of sound in dry air is only about 343 meters per second. So, if fireworks explode 1,000 meters away, it will only take three millionths of a second for the light to reach the viewer. However, the loud boom will take about three seconds. When fireworks explode, chemical energy is released quickly as light energy, sound energy, and heat. The quick release of energy into the air around the explosion makes the surrounding air expand faster than the speed of sound. This produces a shock wave of sound energy you hear as the “BOOM.”

What is Sound? It is energy in the form of vibrations passing through matter. A quick vibration is a quick back-and-forth movement.

How does sound travel? As sound waves travel through matter, they set particles into motion The moving particles form a pattern Groups of particles that a bunched together alternate with particles that are further apart The area were particles are bunched together are called compressions.

Think Questions? How does a sound wave move through matter? How is a ball dropping to the floor and bouncing back like an echo? When vibrations from an object slow down, how are wavelength and frequency affected?

Answers! 1. A sound wave compresses the particles in matter. Then the particles bounce back to their original position. 2. A ball bounces back up from the floor. Sound that bounces back, or reflects, from a hard surface is an echo. 3. Wavelength becomes longer, and frequency becomes lower.

Frequency The frequency of a wave is the number of waves that pass a point in a certain amount of time.

Wavelength Is the distance between a point on one wave and a similar point on the next wave

Pitch, Volume, and Amplitude Pitch is how high or low a sound is. Volume is a measure of how strong a sound seems to us. Amplitude is the height of a wave measured from its midline.

True or False? The higher is the amplitude of a wave, the quieter it sounds? False- because the higher the amplitude of a wave, the more energy it has, and the louder it sounds. Objects that vibrate more quickly have fewer frequencies? False-because objects that vibrate more quickly have higher frequencies.

THICK QUESTION How would a drum played on Earth sound different from a drum played in outer space? A drum played on Earth would create sound because there is air through vibrations can pass. However, outer space is empty, so a drum played there would create no sound.

BROUGHT TO YOU BY… GRACE SCHNEIDER