Reflection and refraction of waves

The diagram shows the refraction of a light wave as it passes from material A to material B.

Which statement is correct?

A The frequency of the wave increases as it passes from material A to material B.

B The period of the wave decreases as it passes from material A to material B.

C The speed of the wave decreases as it passes from material A to material B.

D The wavelength of the wave increases as it passes from material A to material B.

15* A student shines a ray of white light from air into a glass prism.

White light is made up of many different colours of light. The diagram shows the path of four of these colours of light in the prism.

The speed of these four colours of light in air is 3.0 10⁸ m / s.

The table shows the wavelengths and the speeds of these four different colours of light in the glass prism.

Colour	Wavelength in glass prism (nm)	Speed in glass prism (m / s)
Red	640	1.986 108
Yellow	589	1.984 108
Blue	486	1.976 108
Violet	434	1.971 108

Describe:

• what the student sees when the light travels into the glass prism

• the relationship between the wavelengths of the four different colours of light and their speeds in the glass prism.

Explain your answer using the data in the table and ideas about refraction.

In summer, a layer of warm air forms above a layer of dense cool air in the atmosphere. This causes radio waves to bend instead of travelling in straight lines.

Which statement explains why the radio waves bend?

A The frequency of the wave changes.

B The speed of the wave changes.

C The wave is absorbed by the cool air.

D The wave spreads out.

A teacher uses a ripple tank to show refraction of water waves. Fig. 14.1 shows a ripple tank.

Fig. 14.1

Explain how the ripple tank and a thick sheet of plastic can be used to show refraction of water waves.

In glass, violet light refracts more than red light as it passes from air into glass.

Which statement explains why?

A Red light has a shorter wavelength.

B Red light slows down more than violet light.

C Violet light has a longer wavelength.

D Violet light slows down more than red light.

A student refracts light with a rectangular glass block.

He looks for a relationship between angle of incidence and angle of refraction.

Suggest how the student completes this experiment and the apparatus he uses.

The student needs to write a risk assessment for the experiment.

Complete the table to give one risk, the hazard it could cause and a control measure for the

The table shows the results from the experiment.

What could the student conclude from the graph?

The angle of refraction at 40° is incorrect.

Use the curve of best fit on the graph to estimate the actual angle of refraction at 40°.

Another student uses red light in the experiment.

She then repeats the experiment with blue light.

Describe and explain the difference in the refraction of the red light and blue light.