When an incident pulse pulls the light
string up, the light string, because it is light, moves up faster than
if it were part of the heavy string. Thus the light string pulls the
heavy string up. On the other hand, when the incident pulse pulls the
light string down, it moves down faster than if it were a part of the
heavy string and, therefore, it pulls the heavy string down. The pulling
of the light string on the heavy string generates the none inverted
reflected pulse.
Since some of the energy is taken by the transmitted
pulse,the reflected pulse has a smaller height than
the incident pulse.
Reflection occurs at the boundary between two
different media, for example, at a point joining two different strings.
An incident pulse is inverted
upon reflection at the boundary.
Heavy string
Heavy string
When an incident pulse pulls the heavy
string up, the heavy string, because of its mass, moves up slower than
if it were part of the light string. Thus the heavy string pulls the
light string down. On the other hand, when the incident pulse pulls the
heavy string down, it moves down slower than if it were a part of the
light string and, therefore, it pulls the light string up. The pulling
of the heavy string on the light string generates the inverted reflected
pulse.
An incident pulse is not inverted
upon
reflection at the boundary.
