Lesson One : Activities and Quizzes
Activity 5: The relationship of a wave's wavelength and frequencyRequired materials: In addition to the items listed above in Activity 3, a marker and a large sheet of graph paper or a piece of paper with grid lines drawn on it will be needed.
Procedure: Have two students set up the standing wave pattern as in Activity 3 above by vibrating the SlinkyŽ as slowly as possible. Measure the wavelength and the frequency of the wave as before (keeping the frequency constant as this is done). Then have the student increase the rate of vibration and measure the wavelength and frequency again. Repeat this process several times, recording each pair of values on the top of the sheet of graph paper. Use the marker to draw a pair of axes on the graph paper.
Label the vertical axis "wavelength" and the horizontal axis "frequency." Plot the values of wavelength and frequency found above on the graph. Note how the relationship between wavelength and frequency forms a roughly straight line on the graph. This demonstrates that the wavelength of a wave is inversely proportional to the frequency of the wave: wavelength ~ 1/f. If the frequency is increased, the wavelength shortens and if the frequency decreases, the wavelength lengthens.