Which of the following would conduct sound waves fastest?
hot air (70°C)
hot metal (70°C)
cold air (10°C)
cold metal (10°C)
Hot metal (70°C) would conduct sound waves the fastest because metals are better conductors of sound than gases. Additionally, hot temperatures increase the speed of sound in metals.
To determine which of the given options would conduct sound waves fastest, we need to understand the concept of speed of sound propagation in different mediums.
The speed of sound depends on the properties of the medium through which it travels. In general, sound travels faster in solids compared to gases because the particles in a solid are tightly packed, allowing sound waves to propagate more efficiently.
Additionally, the speed of sound is influenced by the temperature of the medium. As temperature increases, the speed of sound generally increases, and as temperature decreases, the speed of sound decreases.
Let's analyze the options based on these principles:
1. Hot air (70°C): Hot air is a gas, and as mentioned earlier, sound travels slower in gases compared to solids. However, hot air has a higher temperature, which increases the speed of sound. So, while sound would propagate slower in hot air due to its gaseous nature, the higher temperature would partially compensate for this, resulting in a faster speed compared to cold air.
2. Hot metal (70°C): Metal is a solid, and sound travels faster in solids compared to gases. Therefore, hot metal would conduct sound waves faster than both hot and cold air. Additionally, the higher temperature of the metal would further increase the speed of sound.
3. Cold air (10°C): As mentioned earlier, sound travels slower in gases compared to solids. Cold air has a lower temperature, which decreases the speed of sound even further. Therefore, sound would propagate slower in cold air compared to hot air.
4. Cold metal (10°C): Similar to hot metal, cold metal is also a solid. Consequently, sound would still propagate faster in cold metal compared to both hot and cold air. However, the lower temperature of the metal would decrease the speed of sound compared to hot metal.
In conclusion, the hot metal (70°C) would conduct sound waves fastest among the given options.