Sound Class 8 Worksheet

Sound Class 8

Sound is a physical, longitudinal, mechanical wave produced by vibrations traveling through a medium (solid, liquid, or gas). As a form of energy, it propagates as pressure oscillations or, scientifically, alternating compressions and rarefactions that stimulate hearing receptors, creating auditory sensations. It is characterized by pitch (frequency) and volume (amplitude).

🎯 Learning Objectives

🎯 Learning Objectives

• Understand how sound travels.
• Learn about compressions and rarefactions.
• Identify factors affecting speed of sound.

🧩 Competencies

• Conceptual Understanding
• Scientific Reasoning
• Observation Skills
• Application Skills

📊 Learning Outcomes

• Explains sound as a longitudinal wave.
• Identifies medium requirement.
• Analyzes factors affecting speed.

📌 Evidence

• Student explanation of sound travel
• Worksheet performance
• Concept-based answers

Animated Sound Particle Movement

Sound travels through particles of a medium. Compressions and rarefactions help sound move forward.

🧠 Click and Flip Concept Cards

Click each card to revise the key point.

Medium

I am needed for sound to travel.

Longitudinal

I am a type of wave in sound.

Compression

I am region of high pressure.

Rarefaction

I am region of low pressure.

Solid

Sound travels fastest in solid.

Vacuum

Sound cannot travel in vacuum.

📝 Who Am I? MCQ Quiz

Answered: 0/10

1. I am needed for sound to travel.

Vacuum Medium Light Energy

2. I am a type of wave in sound.

Transverse Longitudinal Circular Random

3. I am region of high pressure.

Rarefaction Compression Vacuum Noise

4. I am region of low pressure.

Compression Rarefaction Sound Energy

5. Sound travels fastest in:

Gas Liquid Solid Vacuum

6. Temperature increases → speed:

Decreases Increases Same Stops

7. Humidity effect:

Decreases speed Increases speed No effect Stops sound

8. Does loudness affect speed?

Yes No Sometimes Always

9. Elasticity effect:

Slower Faster No change Stops

10. Sound cannot travel in:

Air Water Vacuum Steel

🧠 HOTS

1. Why astronauts cannot hear sound in space?

Because there is no medium in vacuum.

2. Why sound travels faster in solids?

Particles are closely packed.

3. Why sound is clearer in winter?

Due to higher density and humidity.

4. Why loudness does not affect speed?

Speed depends on medium, not amplitude.

5. Why wind affects sound?

Wind changes effective speed of sound.

⚡ Quick Revision Zone

Remember

• Sound needs a medium to travel.
• Sound is a longitudinal wave.
• Compression is high pressure region.
• Rarefaction is low pressure region.

Speed of Sound

• Sound travels fastest in solids.
• Temperature increases → speed increases.
• Humidity increases speed.
• Loudness does not affect speed.

Concept by Teacher Ritu, Designed by Shaleen Shejhar