9. Prove that sound travels in solids too.

Sound can indeed travel through solids, and this phenomenon can be demonstrated through various experiments. Here's a simple experiment to illustrate that sound travels through solids:

Experiment:

Materials:

1. A solid object (such as a metal rod or wooden dowel)
2. A table or a solid surface
3. A partner

Procedure:

1. Place one end of the solid object (metal rod or wooden dowel) against the solid surface (table).
2. Ask your partner to place their ear against the other end of the solid object.
3. Tap the solid object gently against the table or another hard surface.

Observation: Your partner should be able to hear the tapping sound conducted through the solid object, even though the sound source is not directly connected to their ear.

Explanation: In this experiment, when you tap the solid object against a hard surface, sound waves are generated through the vibrations in the material. These vibrations travel through the solid, reaching the other end where your partner's ear is in contact with the solid object. The solid acts as a medium for the transmission of sound waves.

This experiment demonstrates that sound can propagate through solids by causing the particles in the material to vibrate. Solids transmit sound waves more efficiently than gases because the particles in solids are closely packed, allowing for a more effective transfer of mechanical vibrations.

This property of sound transmission through solids is utilized in various real-world applications, such as the use of seismic waves to study the Earth's interior, the transmission of sound through structural elements in buildings, and the operation of certain musical instruments that rely on the vibrations of solid materials.