12.4. Reflection of Mechanical Waves http://www.ck12.org
Review
Questions
- Draw a diagram showing a surface with a normal line. On the diagram, show a wave ray striking the surface
with an angle of incidence of 60◦. Draw the reflection ray on the diagram and label the angle of reflection. - Light strikes a mirror’s surface at 30◦to the normal. What will the angle of reflection be?
- If the angle between the incident ray and the reflected ray is 90◦, what is the angle of incidence?
- When a water wave is reflected from a concrete wall, will the reflected wave be inverted or upright?
- If you tie a heavy spring to a light spring and send a wave pulse down the heavy spring, some of the wave will
be reflected when the wave passes into the lighter spring. Will the reflected pulse be upright or inverted?
- reflection: The change in direction of a wavefront at an interface between two different media so that the
wavefront returns into the medium from which it originated. - law of reflection:Says the angle at which the wave is incident on the surface equals the angle at which it is
reflected. - angle of incidence:The angle formed by a ray incident on a surface and a perpendicular to the surface at the
point of incidence. - angle of reflection: The angle formed by a reflected ray and a perpendicular to the surface at the point of
reflection.