Practice Question

1.Define the term reflection

Reflection is when a wave hits a boundary in a medium and bounces off the surface, without changing speed or wavelength.

2. Explain the difference between regular reflection and scattering.

Regular Reflection (Specular Reflection)

Occurs when light rays hit a smooth, polished surface (like a mirror or still water).

The reflected rays remain parallel, following the law of reflection (angle of incidence = angle of reflection).

Produces clear images, like your reflection in a mirror.

Scattering (Diffuse Reflection)

Occurs when light strikes a rough or uneven surface (like paper, fog, or a dusty road).

The light rays are reflected in multiple directions instead of staying parallel.

No clear image is formed; instead, light spreads out, making objects visible from different angles.

3. Aluminium foil is squashed into a ball and then unfolded to make a bumpy surface. If a beam of light is shone onto the foil, what would happen?

Scattering or diffuse reflection

4. Explain why the amplitude of a wave decreases as it passes through a material.

The amplitude of a wave decreases as it passes through a material due to energy loss caused by absorption.

As the wave travels through the material, some of its energy is transferred to the medium’s particles.

This energy conversion (often into heat or vibrations) reduces the wave’s amplitude.

The material’s thermal energy store will increase.

Example: Sound waves lose energy as heat when passing through walls.