Sound has energy in Sound – Class 8 Science Experiment
Chapter Name: Sound
Activity Name: Sound has energy in Sound
Activity Description:

This experiment aims to demonstrate the energy of sound and its ability to cause vibrations. By creating a simple diaphragm using a plastic bottle, a cell phone, and a balloon, we will observe how sound can make sand particles or sugar crystals on the diaphragm move when the phone plays music inside the bottle.
Required Items:
- Plastic bottle (empty and clean)
- Cell phone with music playback capability
- Scissors
- Balloon
- Rubber band
- Sugar crystals or small sand particles
Step by Step Procedure:
- Take the plastic bottle and clean it thoroughly to remove any residue.
- Using the scissors, carefully cut off the top of the bottle to create a glass-like structure.
- Set up the cell phone with a playlist of songs or music ready to play.
- Place the cell phone inside the bottle so that the speakers face downwards.
- Take the balloon and stretch it over the mouth of the bottle.
- Secure the balloon tightly in place using a rubber band, ensuring it covers the bottle’s mouth completely and acts as a diaphragm.
- Sprinkle some sugar crystals or sand particles on the surface of the balloon diaphragm.
- Observe the arrangement of particles while no music is playing (without the cell phone inside the bottle).
- Start playing the music on the cell phone at a high volume and observe the movement of the particles on the diaphragm.
- Repeat the observation without the cell phone to compare the results.
Experiment Observations:
- Without the cell phone inside the bottle, the sugar crystals or sand particles on the diaphragm remain stationary.
- When the cell phone plays music inside the bottle, the diaphragm vibrates, causing the sugar crystals or sand particles to move and dance.
Precautions:
- Handle the scissors carefully to avoid any accidents or injuries.
- Ensure that the plastic bottle is clean and dry before use.
- When placing the cell phone inside the bottle, take care not to damage the phone or its speakers.
- Use a balloon that is not too thin or too thick to function effectively as a diaphragm.
- Do not use excessive volume levels on the cell phone to prevent potential damage to hearing or the phone’s speakers.
Lesson Learnt from Experiment:
The experiment demonstrates that sound has energy, capable of causing vibrations in materials like the diaphragm made from a balloon. The movement of the sugar crystals or sand particles showcases the power of sound energy and how it can influence the physical environment around it. This experiment helps understand the concept of sound energy and its effects in a simple and engaging manner.