Page 49 - Science Course 3 (Book 2)

Mo10-L1b: What are the Properties of Waves?

Key Concept The law of ref ection states that the angles made by
the incident wave and ref ected wave with the normal
What are the Properties of Waves? are always equal.

How can you describe waves by
their properties?

The change in direction of a wave as it changes
speed in moving from one medium into another is
called refraction.
Narrow gap waves
spread out be-
yond the gap. This
Wave Interaction with Matter spreading is called
diffraction
Some of the energy carried by waves is transmitted,
some is absorbed, and some is ref ected by the Diffraction is the
particles in matter. change in direction
of a wave when
it travels past the
edge of an object
or through an open-
ing.
Ref ection: Diffraction is most
The plane ref ects obvious when the
the radio waves gap is approximate-
back toward the ly the same size as
antenna. the wavelength of
the wave.

Absorption:
The plane and particles in
the air absorb some of the
energy. The ref ected wave
carries less energy than
the original wave.

Transmission:
Radio waves carry energy
from the antenna to the
plane

Wide gap compared to wavelength results in waves
traveling straight on or rectilinear propagation.

41