Question

What keeps the air molecules from continuing to travel in the direction of propagation of the sound wave?

• A. Bouncing of molecules at their position
• B. Air molecules collision and bouncing away from each other
• C. The mass of air molecules
• D. The gravity acting on the air molecules

Answer 1

The correct option is B

Air molecules collision and bouncing away from each other

Sound waves propagate through air molecules colliding with their neighbouring molecules. When the molecules collide, they also bounce away from each other which is also known as a restoring force. This keeps the molecules from continuing to travel in the direction of propagation of a wave.