Questions & Answers

Sound waves travel faster in air than in water. True or False?

Answer Verified Verified
Hint: Sound waves require a medium to travel. They cannot travel in vacuum. Sound waves travel through the molecules in a medium. The more closely packed the molecules of the medium are, the more is the speed of sound waves in the medium. Molecules of water are more closely packed than molecules of air. This means that the density of water is more than the density of air. Speed of sound waves is proportional to the density of the medium.

Complete step by step answer:
Most of us would have tried touching a fish inside water with high speed and accuracy. Unfortunately, most of the time, we fail. The simple concept running behind this wonderful escape is reception of sound. The fish sense the sound easily when we touch the surface of the water and escape quickly. Other interesting applications of sound waves in water include communication among aquatic species, underwater navigation and tracking of submarines, detection of earthquakes, etc.
The speed of sound waves in water can be compared to that in air. Sound waves require a medium to propagate and they cannot travel in vacuum. The most important factor which determines the propagation of sound waves is the density of the medium. We know that molecules in air are loosely packed while those in water are more closely packed than the former. Hence, the density of air is less when compared to that of water. Sounds propagate through oscillations and the waves vibrate and move from one molecule to the other. In water, molecules are closer and it becomes easy and less time-consuming for the sound waves to travel than in air, where the molecules are not much closer. The speed of sound waves in water is approximately 4 times higher than that in air. So, the answer is False.

Additional Information: Speed of sound is dependent on pressure and temperature as well. In water, it is also dependent on the salinity of the water. Speed of sound in seawater is more than the speed of sound in freshwater. Sound waves travel slowly in air, faster in water and even faster in solids.

Note: The question can be given in the other way also. i.e. The question can be: Sound waves can travel faster in water than in air. True or False? Here, the answer is True whereas the answer to the first question is False. Students should find time to read the question properly before answering such types of questions. They need not hurry.