Reflection and refraction between taut strings
Two strings of the same diameter but different mass densities are tied up
and under tension. A wave pulse moves initially along the string on the
left and reflection and refraction happen when it reaches the junction.
-
You can select below the reflection coefficient R and the phase
velocity v1 = v1 on the left string. In the
second string the phase velocity will be v2 = v2 =
(1+R)/(1-R) v1 and the quotient of
mass densities m2/m1 = μ2/μ1
= (v1/v2)2.
-
You may also choose pulse's amplitude A, width L and
profile, as well as the number of discretization points N and
the time interval between animation frames Δt.
-
To get information on an element, put over it the mouse pointer to see
the corresponding tooltip.
Activities
-
You should try at least the following cases: R = 0, -1<R<0,
0<R<1, R = -1 and R = 1.
-
How changes the quotient m2/m1 and the relation between
velocities with R?
-
When comes in counterphase the reflected pulse?
-
In which cases is larger the amplitude of the transmitted wave? Why?
This is an English translation of the Basque original for a course
on mechanics, oscillations and waves.
It requires Java
1.5 or newer and was created by Juan
M. Aguirregabiria with Easy
Java Simulations (Ejs) by Francisco
Esquembre. I thank Wolfgang Christian and Francisco Esquembre for
their help.