Observing the vibration of tuning fork in Sound – Class 9 Science Experiment

Chapter Name: Sound

Activity Name: Observing the vibration of tuning fork in Sound

Activity Description:

Required Items:

1. Tuning fork
2. Rubber hammer
3. Smoked glass
4. Small piece of steel wire

Step by Step Procedure:

1. Take the tuning fork and the rubber hammer.
2. Gently strike one of the prongs of the tuning fork with the rubber hammer.
3. Bring the vibrating tuning fork near your ear and observe if you hear any sound.
4. Touch one of the prongs of the tuning fork with your finger and share your feelings about the sensation with your friends.
5. Attach a small piece of steel wire to one of the prongs of the tuning fork as shown in figure 2.
6. While the tuning fork is vibrating, quickly draw a straight line on the piece of smoked glass using the wire.
7. Keep the end of the wire just touching the glass while drawing the line.
8. Observe the line formed on the smoked glass, which represents the wave pattern of the vibrations.
9. Repeat the experiment with the tuning fork when it is not vibrating and observe the difference in the line drawn on the glass.

Experiment Observations:

1. The participants will observe that striking the tuning fork produces sound, which can be heard when it is brought near the ear.
2. When touching one of the prongs of the vibrating tuning fork, the participants will feel the vibrations in their fingers.
3. Drawing on smoked glass while the tuning fork vibrates will result in a wave-like pattern, indicating the vibration’s motion.

Precautions:

1. Handle the tuning fork and the rubber hammer carefully to avoid injury.
2. Attach the steel wire securely to the tuning fork to ensure proper visualization of vibrations.
3. When drawing on smoked glass, make sure the wire just touches the glass to get a clear wave pattern.

Lesson Learnt from Experiment:

The experiment demonstrates the correlation between sound and vibrations. Striking the tuning fork causes it to vibrate, producing sound waves that can be heard. The visualization of vibrations on smoked glass further emphasizes the relationship between sound and the physical motion of the tuning fork.