Physics I
Name ___________________________
Period __________
Slinky Lab Activities
You and your lab partner should hold opposite ends of a spring and stretch it out on the floor to an appropriate
length. The spring should be tight, but be careful not to exceed the elastic limit. DO NOT LET GO OF EITHER
END OF THE SPRING.
Part 1 – Wave Types and Wave Characteristics
1. Pinch a clump of coils together with your free hand and release the clump of coils. Do not let go of either side
of the spring. Observe the pulse that travels back and forth through the spring. Is this a transverse or
longitudinal wave?
2.
Sketch the wave pulse here:
3.
Have one person give the end of the spring a few sideways shakes. Is this a transverse or longitudinal wave?
4.
Sketch the wave pulse here:
5.
How do you need to move your arm to make a large amplitude wave?
6.
Make a wave with a low frequency by shaking slowly. Does this wave have a long or a short wavelength?
7.
Make a wave with a high frequency by shaking quickly. Does this wave have a long or a short wavelength?
8.
Write a summary statement: as the frequency of the wave increases, the wavelength _____________.
Part 2 – Wave speed
9. Plan a short experiment to test how the speed of a wave depends on the amplitude of the pulse. You have both a
stopwatch and a meter stick at your disposal. Make sure you have at least three different values of the
amplitude (your independent variable). Write your procedure here:
10. Make a data table in the space below, then perform your experiment.
11. Is the speed of the wave pulse affected by the amplitude of the pulse? What evidence do you have?
12. Do a second short experiment to answer the question: “Does the speed of the pulse depend on the tension
(tightness) of the spring?” Make a data table here, again with at least three values of the independent variable:
13. Is the speed of the wave pulse affected by the tension of the spring? What evidence do you have?
14. Write a statement about the factors that affect and do not affect the speed of a wave:
The speed of a wave on a spring depends on __________________. The speed of a wave on a spring does NOT
depend on __________________.
Part 3 – Interference
15. Have one person send a single transverse wave pulse along the spring. At the same time, have your partner
create a wave pulse at the other end on the same side of the spring as the first pulse. This is called interference.
Would you call this constructive or destructive interference?
16. Describe the interference of the two wave pulses. How does the pulse amplitude during interference compare
with the individual amplitudes before and after this interaction?
17. Repeat the experiment, but with the two pulses traveling on opposite sides of the spring. What happens to the
amplitudes when the pulses meet?
18. Would you call this constructive or destructive interference?
19. During interference, do you think that the wave pulses are bouncing off of each other or passing through?
20. Let’s test it. Send two wave pulses toward one another again, but this time have one person send a transverse
pulse and the other send a longitudinal pulse. Carefully watch the two wave pulses after they meet. Are they
passing through each other or bouncing off each other?
Part 4 – Reflection
21. With the far end of the spring held firmly in place by your lab partner (fixed-end), send a single pulse down one
side of the spring. Observe the reflected pulse. Is the amplitude of the reflected pulse different from the
original amplitude? If different, how so?
22. Is the reflected pulse on the same or opposite side from the original pulse?
23. Attach a light string about 1 meter in length to the far end of the spring and hold the end of the string instead of
the spring. (This now represents a free end instead of a fixed end.) Repeat the original procedure of sending a
single wave pulse down the spring and observe the reflected pulse. Is the reflected pulse on the same or
opposite side form the original pulse?
24. Write a statement about the difference between fixed end and free end reflection.
Lab Reflection Questions – remember that these should be in paragraphs and in total be ½ to ¾ of a page.
1. What is the purpose of this lab?
2. Explain and state in detail what concept you learned.
3. How could you apply this science lesson to yourself or the world in general?