Sound and Vibration
Grade 2 · Science · Study Guide
Where does sound come from? Learn how vibrations make sounds and how we hear them!
Sound is made when objects vibrate — that means they move back and forth very quickly. When you pluck a guitar string, it vibrates and creates sound. When you bang a drum, the drum skin vibrates and makes a booming sound. Vibrations travel through the air as waves and reach your ears, which is how you hear sounds.
Sounds can be loud or soft. Scientists call loudness volume. Sounds can also be high-pitched (like a whistle) or low-pitched (like a tuba). Pitch is how high or low a sound is. A small, tight guitar string makes a high-pitched sound. A thick, loose string makes a low-pitched sound.
Sound needs matter to travel through. It can travel through solids, liquids, and gases. Sound travels fastest through solids and slowest through gases like air. Sound cannot travel through empty space — that is why space is completely silent!
| Material | State | How Well Sound Travels |
|---|---|---|
| Steel rail | Solid | Very well — fastest |
| Water | Liquid | Well — faster than air |
| Air | Gas | Okay — slower than solids or liquids |
| Outer space | Vacuum (no matter) | Not at all — no sound! |
Key terms
- sound
- Energy that travels as vibrations through matter
- vibration
- A rapid back-and-forth movement that creates sound
- volume
- How loud or soft a sound is
- pitch
- How high or low a sound is
- sound wave
- The pattern a sound makes as it travels through matter
- echo
- A sound that bounces off a surface and comes back to you
Flashcards
- Sound
- Energy created by vibrations that we can hear
- Vibration
- A fast back-and-forth movement that creates sound
- Volume
- How loud or soft a sound is
- Pitch
- How high or low a sound is
- Sound wave
- How sound energy travels through matter
- Echo
- Sound that bounces off a surface and returns to your ears
Practice questions
What causes sound to be made?
- Objects spinning
- Objects vibrating
- Objects melting
- Objects freezing
Show answer
Answer: Objects vibrating
All sounds are caused by vibrations — rapid back-and-forth movements that create energy waves.
Sound can travel through outer space.
Show answer
Answer: False
Sound needs matter (solid, liquid, or gas) to travel through. Space is a vacuum with no matter, so sound cannot travel there.
How high or low a sound is called its ___.
Show answer
Answer: pitch
Pitch describes whether a sound is high (like a whistle) or low (like a bass drum).
What is volume when talking about sound?
- How high the sound is
- How fast the sound travels
- How loud or soft a sound is
- How long the sound lasts
Show answer
Answer: How loud or soft a sound is
Volume is the measure of a sound's loudness. A whisper has low volume; a shout has high volume.
Sound travels faster through solids than through air.
Show answer
Answer: True
Sound travels much faster through solids because the particles are packed tightly together.
Fun facts
- A lion's roar can be heard up to 5 miles away!
- Sound travels about 767 miles per hour through air — that is why you see lightning before you hear thunder!
- Whales communicate by singing — their songs can travel hundreds of miles through the ocean!
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