Wave in a Ripple Tank
Obj:  Measure f, λ, and v of water waves
Materials:  ripple tank, washer, stroboscope

Methods
I.  Wavelength
1.  Produce traveling waves approximately 2 cm apart by adjusting the motor speed of the ripple tank.
2.  Using a stroboscope, "hold" the wave pattern still, then have your partner mark your data sheet 3 or 4 λ apart.  Wavelengths are measured from "bright to bright" areas.

Record the: # waves:_____,  total distance: __________cm;                                      1 λ =  _______cm

3.  Produce standing waves using the long block as described.  What evidence indicates they are standing waves?

II.  Frequency
1.  Hold the wave pattern stationary with the stroboscope.
2.  Record the time for 10 rotations.     ________s   (Use a countdown method.)

Count the number of slots on the strobe _______ x number of rotations = total number of waves _______

Frequency  = number of waves / total time

Analysis
1.  Calculate the period and wave speed in Method II.
2.  What do the "bright" and "dark" lines represent in the standing waves of Method I:Question 3?
3.  Determine the magnification ratio of the image wave / real wave using a washer, then determine the actual λ in the ripple tank from Method I.   How does this affect your calculations for f, T, and v?

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