South Pasadena Honors Physics Name __________________________ Partner’s Name __________________________ Date “Slinky Physics” ___/___/___ Period ______ Labette #1 Hints: If you maintain the same tension in the slinky, this means the medium remains the same. The term “phase” refers to which side of the slinky the bulge is on. Always work with the slinky on the ground. There should be about 3-4 meters of distance between the two partners. 1. Create a longitudinal pulse from one end of the slinky by pinching together many coils of the spring and then letting them go. This is also known as a ____________________ wave. Record what you observe. 2. What happened to the shape of the pulse as it traveled down the slinky? 3. Now create a transverse wave pulse down the slinky, by holding one end of the slinky and quickly pulling it to one side and then returning the end to its original position. What happened to the shape of the pulse as it traveled down the slinky? 4. Determine the time it takes a pulse to travel down the slinky. Then change the amplitude of the pulse and determine the travel time again. Do this for each of the two kinds of waves. Time (small amplitude) ________ Time (large amplitude) ________ Time (small amplitude) ________ Time (large amplitude) ________ 5. Did the change in amplitude change the speed of the wave? ___________ 6. Change the medium of the spring by stretching it to a different length. Determine the speed of each kind of pulse in this new medium. Speed = d/t = _________ = Speed = d/t = _________ = Speed = d/t = _________ = Speed = d/t = _________ = How does changing the medium affect the speed of the wave? 7. Tie a string about 1 meter long to one end of the slinky. Have one partner hold the string and keep a tension on the slinky. From the other end, send a transverse pulse down the slinky. What happens when the pulse arrives at the boundary between the two media? 8. Repeat step # 7 and pay attention to the phase of the original pulse compared to the phase of the reflected pulse. In other words, if you pulled the slinky to the right, which direction did the slinky travel when it came to the string? 9. Now remove the string and repeat step # 7 again, but this time have your lab partner hold one end of the slinky securely without letting it move. Watch the phases of this wave motion. How do the phases of the original and reflected pulses compare when the reflection is from a rigid barrier (your firm hand)? How do they compare when the one end is not rigid? 10. Now, both of you send a pulse simultaneously from each end of the slinky. Experiment with pulses of the same and different sizes and pulses that are in phase and not in phase. Try this with both longitudinal and transverse waves. a. What happens to the two pulses when they meet? b. What happens to the two pulses after they have passed through one another? 13. Lastly, produce a periodic wave by shaking the slinky back and forth, left and right at a uniform rate. Measure the frequency of the wave (# of cycles per second) and make an approximation of the wavelength. Repeat the procedure using a higher and then a lower frequency. How is the wavelength of a wave in a given medium related to its frequency?