Dilys rests a fingertip on the front of a speaker playing a steady tone. The cone buzzes against her finger, snapping back and forth too fast to watch.
That buzzing cone is doing more than tickling a fingertip: it is making a wave. This lesson says where waves come from.
The speaker cone oscillates: it moves forward and back about its rest position, over and over.
Each swing of the cone disturbs the air beside it.
The disturbance does not stay by the cone. It travels outward through the air, away from the cone.
A disturbance that travels outward through a material is a wave. The sound reaching your ears across the room is a sound wave.
The vibrating object that makes the wave is called the source.
The same story runs in other materials. A fingertip bobbing in bathwater sends ripples out across the surface. A plucked string sends a wave running along the string.
Beata bobs a kayak paddle tip up and down in a lake, and ripples spread outward. Name the vibrating source and the material the wave travels through.
The paddle tip oscillates up and down: it is the vibrating source.
The disturbance travels outward across the water.
The source is the bobbing paddle tip, and the wave travels through the lake water.
Anselm hums a note. The sound crosses the room. What is the vibrating source of this sound wave?
Humming sets the folds inside his throat vibrating.
The vibrating folds disturb the air beside them, and the disturbance travels outward.
The source is the vibrating folds in Anselm's throat. The wave travels outward through the air of the room.
A phone buzzes on a tabletop, and the buzz travels through the wood to Cosmo's hand at the table's far edge. Which part is the vibrating source of this wave?
A steady drumbeat sends sound waves across a gym. What produces each wave?
Dilys watches ripples spreading from around a fishing float. She says: 'Something at the center must be oscillating to keep making these ripples.' Is Dilys correct?
Which statement says how a wave is produced?
Four things sit on a glass shelf. Which one is producing a wave in the shelf?
What does a vibrating source do to make a wave?