Wave Motion and Standing Waves

1
Wave Motion and Standing Waves
Wave pulse traveling down string, striking
fixed boundary.
Wave pulse traveling down string, striking free
boundary.
2
Take a string, attach one end to an arm which
can vibrate continuously up and down, and attach
the other end to some rigid object.
When the vibrating arm moves up, a pulse is sent
down the string
3
You end up with standing waves in the string.
You may have done this experiment in Physics lab
somewhere.
4
L
n?/2L
?/2
5
Things to note
The wave pulse travels down the string. Does any
matter travel down the string?
As we saw on the previous slide, if both ends of
the string are fixed, a standing wave results.
If the string is infinitely long and the
up-and-down pulses repeat, we get a traveling
wave.
6
The traveling wave moves through the medium.
Does any matter move along with the wave?
No!
?
The wavelength ? is defined as before.
The period is the time for the wave to travel one
wavelength, and f 1/T as before.