- The speed of sound is a term used to describe the speed of sound waves passing through an elastic medium.
- The speed varies with the medium employed (for example, sound waves move faster through water than through air), as well as with the properties of the medium, especially temperature.
- Sound travels slower in lower temperature and faster in higher temperature.
Speed of Sound at Different Mediums:
| MEDIUM | SPEED (m/s) |
|---|---|
| Air | 343 |
| Helium | 962 |
| Water | 1500 |
| Steel | 5600 |
- Sound is propagation of local disturbance in a medium.
- Molecules in a solid are more tightly packed than those in gases.
- So it is easier for solid molecules to collide with neighboring molecules and facilitate the propagation of disturbance.
How to measure sound travel in air:
- The average speed of sound through air is about 1130 feet per second (344 meters per second) at room temperature. However, changes in temperature and humidity will affect this speed.
- Here is a simple way to measure the speed at which sound travels through air. You'll need the following items:
- Two blocks of wood, or other items that make a loud, sharp sound when struck together.
- A stopwatch
- A friend to help with the experiment
- A tape measure
- Instructions:
- Find a large empty area, such as a field or large court.
- Choose two spots on opposite ends of the area where each person will stand.
- Measure the distance between the two spots using a tape measure. Alternatively, you can count off measured steps between the two spots.
- Have your friend take the blocks and stand at one spot, holding them up high.
- Take the stopwatch and stand at the other spot. Make sure you have a clear view of the blocks.
- Signal your friend to bang the two blocks together hard.
- Start the stopwatch as soon as you see the blocks hit each other.
- Press stop as soon as you hear the sound from the blocks.
- Calculate the speed of the sound by dividing the distance between you and your friend by the elapsed time. To get a more accurate measurement, repeat the above steps a few times and then take an average of the results.
Other Examples of Measuring the Speed of Sound:
 |
| Measuring of Speed of Sound Using Microphone |