What are waves?
2 marks · NormalSound from a loudspeaker is heard on the other side of a room. Explain, in terms of energy and matter, what happens as the sound travels from the loudspeaker to the listener.
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Energy is transferred by the sound wave but air particles do not travel across the room.
Also accept: Energy moves but the air stays in place and vibrates
Common mistakes: Saying air moves across the room
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Marking points
B1 · 1 mark · States energy is transferred by the sound wave.
B2 · 1 mark · States air particles do not travel across the room (vibrate about fixed position).
Worked solution
The vibrations of the loudspeaker cause the air molecules to vibrate back and forth. The vibrations transfer energy through the air, but the air molecules do not move across the room; they only vibrate in place.