Sound Energy

The blare of an alarm clock, the beep of a car horn, the quack of a duck, and the rumble of thunder during a storm are all ​ (a)   . Sound is energy in the form of ​ (b)   passing through matter. A vibration is a quick back-and-forth ​ (c)   . Sounds occur when objects vibrate. Sound travels through solids, liquids, and gases. Sound ​ (d)   through empty space, where there is no matter.

Pluck a guitar string, and the string starts to vibrate. The vibrating string passes energy to the air around it. The sound energy travels outward as sound waves. A sound wave is a ​ (e)   that moves sound energy through matter. When the waves reach your ears, the waves make your eardrum vibrate, and you hear the sound made by the guitar string.

• sounds
• vibrations
• movement
• cannot travel
• disturbance

Tags

NGSS.MS-PS4-2

How Sound Travels

As sound waves move through matter, they set ​ (a)   into motion. The moving particles form a ​ (b)   . Areas with groups of particles that are bunched together alternate with areas of particles that are farther apart. The areas where particles bunch together are called ​ (c)  

Sound waves travel at different ​ (d)   through matter. Sound waves travel quickly through most ​ (e)   and liquids. Sound waves tend to travel more slowly through gases.

• particles
• pattern
• compressions
• speeds
• solids

Tags

NGSS.MS-PS4-1

NGSS.MS-PS4-2

Read the text and complete the sentences.

1. The moving ​ (a)   form a pattern.

2. ​ (b)   are the areas where particles bunch together.

3. Sound waves move ​ (c)   through most ​ (d)   and solids.

4. Through ​ (e)   , sound waves tend to travel more slowly.

• particles
• Compressions
• faster
• liquids
• gases
• matter
• materials
• Areas
• Speeds

Tags

NGSS.MS-PS4-2

Match the following.

• Crests

• high points on waves shown on oscilloscope screens

• Wavelength

• number of waves that pass a point in a certain amount of time

• Oscilloscope

• piece of equipment that shows waves on a screen

• Frequency

• distance between similar points on two waves next to each other

• Sound wave

• a disturbance that moves sound energy through matter

Tags

NGSS.MS-PS4-1

Frequency and Wavelength

Waves can travel in different ​ (a)   . They can carry different types and amounts of energy. But all waves have certain ​ (b)   . Frequency and wavelength are two of these properties.

The ​ (c)   of a wave is the number of waves that pass a point in a certain amount of ​ (d)   . Frequency is often described as the number of complete cycles a wave makes in one second. A cycle is one vibration.

Wavelength is the ​ (e)   between a point on one wave and a similar point on the next wave.

• ways
• properties
• frequency
• time
• distance
• speed
• areas
• particles

Tags

NGSS.MS-PS4-1

Match the following

• crest

• 2

• wavelength

• 4

• cycle

• 5

• trough

• 1

• compression

• 3

Tags

NGSS.MS-PS4-1

When vibrations from an object slow down, how are wavelength and frequency affected?

When vibrations slow down, ​ (a)   becomes ​ (b)   and ​ (c)   becomes ​ (d)   .

• wavelength
• longer
• frequency
• lower

Match the following

• Objects that vibrate more quickly have

• a higher frequency and a higher pitch.

• Objects that vibrate more slowly have

• low-pitched sounds.

• The size and shape of objects

• a lower frequency and a lower pitch.

• Tubas make

• high-pitched sounds.

• Dolphins

• affect the pitch you hear.

1.​ (a)   is a measure of how strong a sound seems to human.

2.​ (b)   is the height of a wave measured from its midline.

3. ​ (c)   is how high or low a sound is.

4. If you change the frequency or ​ (d)   of a sound wave, you change its pitch.

5. If you change the amplitude, or ​ (e)   , of a sound wave, you change its volume.

• Volume
• Amplitude
• Pitch
• wavelength
• height

Tags

NGSS.MS-PS4-1

You stand outside a room with doors and windows closed.

Why can you still hear sounds made in the room?

Answer explanation

Because sounds travel through solids, not just through gases.

Tags

NGSS.MS-PS4-2