Sound

Complete the sentence to define waves. Waves are vibrations that:

• transfer energy, but not matter, from place to place

• transfer energy and matter from place to place

• transfer matter, but not energy, from place to place

• I'm not sure

Recall which types of wave can travel through a vacuum.

• Radio wave

• Sound wave

• Light wave

• I'm not sure

In the diagram below: 1. Label the waves created by the slinky "transverse" and "longitudinal", as appropriate.

Note: If you have a slinky have a go at creating these waves!

b

a

transverse

longitudinal

Answer explanation

In the diagram:

1.Draw a blue arrow in the "Direction of wave" box to illustrate the direction the wave is moving.

2.Draw a double-ended red arrow in the "Particle movement" circle to illustrate the direction, backand forth, the slinky coils are moving.

Answer explanation

Sound waves transfer energy through the vibrations of particles, such as air molecules. Explain whether sound waves are transverse or longitudinal, and what this means.

Answer explanation

Sound waves are a type of longitudinal wave. This means that the particles vibrate back and forth in the same direction as the wave istravelling.

The top half of the diagram below is an enlargement of the one above, with the points A, B, and C marked. The bottom half shows an uncompleted graph.

- The Y axis is air compression or rarefaction. The degree of density or compression of the air in the silent room is represented by the mid-point of the axis – where the X axis crosses.

- The X axis represents horizontal position – it corresponds exactly to the locations in the diagram in the top half.

We have filled in part of the graph, plotting compression or rarefaction for the areas around A, B, and C.

Use the pen tool to complete the graph by drawing the rest of the curve.

Answer explanation

The diagram below is similar to the previous one, but has two air molecule diagrams, Q and L. They represent the same room with different sound waves passing through. There is one graph below each diagram. As in the previous question, use the pen tool to draw a curve on each graph to illustrate the compression and rarefaction of air molecules. One point for each graph has been added to help you get started.

Answer explanation

List sounds that you think would have a very high amplitude.

List sounds that you think would have a very low amplitude.

Draw a horizontal red line on each of the molecule diagrams and on each graph to show the wavelength (four lines in total).

Answer explanation