Practice Question

1.What changes do we look for in the properties of waves when using waves to investigate the structure of a material?

We look at differences in velocity, absorption and reflection between different types of waves in solids and liquids to provide information on the structure of a material.

2. A wave passes through a material, but takes longer to reach the other side of the material than expected. Suggest what this might indicate about the material.

The velocity of a wave will change depending on the density of the material. As the wave took longer than expected to travel through the material. The material contained a another material inside which had a different density, causing the velocity of the wave to change.

3. A signal generator is used to generate sound waves. Two sound waves are generated with equal amplitude. Each wave passes through a different material. Explain why the transmitted sound waves have different amplitudes.

Denser materials will absorb more of the energy of a wave, causing a bigger decrease in the amplitude. As transmitted waves had different amplitudes it means the two materials had different densities. 

4. Bats use sound waves to detect their surroundings such as solid structures, so they can avoid them. Suggest how this works. 

Bats emit a sound wave which reflects from the solid surface in front of them. The bat will then receive the reflected sound wave and know how far the solid surface is infront. This allows the bat to avoid flying into the solid structure.