Name: __________________________________ Date: ______________
7th Grade Science Period: _____________
Slinky Wave Lab
**Disclaimer**
Please be gentle with the Slinkies and Snake-springs. They are easily tangled and can then no longer be used. DO NOT overstretch the springs or they will become permanently deformed. Handle with care!
This lab was designed to help provide you with a better understanding of the two types of mechanical waves through the motion of a Slinky and Snake-spring. These items will be used in a series of three separate experiments in which you will be asked to investigate how the various characteristics of transverse and longitudinal waves impact one another. During this lab you will calculate the speed, frequency, and amplitude of the waves you produce and observe how wavelength can play a role in the overall speed and power of a wave. As you progress though the three portions of this lab, be sure to refer back to your readings and notes when needing clarification, so you can provide yourself with the best chance to fully grasp the concepts associated with this lab and the two different types of mechanical waves.
For this lab, there are four roles that must be fulfilled in all three of these experiments. The number you received at the beginning of the lab period on the index card will determine your starting role. You and your teammates will then rotate from job to job in the order that appears below. Please stay focused on your role during each of your teammates’ tests to ensure accurate data collection for everyone.
1)
Waver
(Produces the wave being observed)
2)
Time keeper
(Uses stopwatch/timer to keep track of time)
3)
Spotter
(Observes the wave(s) for amplitude, wavelength and/or frequency)
Part 1 – Slinky Transverse Wave Test
In this test you will working to control the AMPLITUDE of your Slinky waves.
Materials:
Slinky Roll of masking tape Stop Watch/timer Meter stick Lab packet Pencil
Procedure:
1) The WAVER and the HOLDER should each grab opposite ends of the slinky and carefully walk to opposite sides of the BLUE tape lines on the floor. (Distance = _______ meters)
2) The spotter should stand about half way between the WAVER and the HOLDER.
3) Place the Slinky of the floor holding onto it securely to make sure it does not slip and rocket back to the WAVER.
4) Once the HOLDER and WAVER are in place, the timer should count down, 3-2-1-GO, and start the timer. 5) On go, the WAVER should move their hand quickly from left to right trying to produce one single wave of a LOW amplitude.
6) The spotter should observe the wave as it moves past them and identify the height of the crest by placing a piece of masking tape on the floor labeled LOW.
7) Measure the distance from the resting point to the crest to determine the wave’s amplitude. Record this number in your data table.
8) Record the time it took for the wave to go from the WAVER to the HOLDER in your data table. (Be precise) 9) Repeat steps 5-7, but this time produce a MEDIUM amplitude wave. In your last test, try to produce a HIGH amplitude wave.
Team Member’s Name Time
(sec)
Speed
(m/sec)
Amplitude
*(cm) Low =
Medium = High= Low = Medium = High= Low = Medium = High= Low = Medium = High=
Analysis:
1) Sketch each of YOUR waves below on the lines. Be sure to label the resting points, the crest/trough, and the measurement you determined for amplitude.
___________________________ ___________________________ __________________________
Conclusion questions:
Directions: Complete the following questions using your observations from the lab and the knowledge you have gained through our class discussions. Your responses MUST BE TYPED and in COMPLETE SENTENCES!
1) Explain how were your able to control the amplitude of the waves you produced? What did you do differently to produce the wave with the highest amplitude?
2) How does the amount of energy you exerted on the Slinky coincide with the amplitude of the wave? How much energy did it require to produce a wave with the highest amplitude?
3) As the HOLDER, how much energy was transferred to you during each of the low medium and high amplitude tests. Which one seemed to transfer the most energy? Why do you think this is?
4) What connections can you make about the speed of your three waves and their amplitude? Do the different waves have different speeds according to their amplitude?
Part 2- Slinky Longitudinal Wave Test
In this test you will working to control the COMPRESSIONS of your Slinky waves.
Materials
:Slinky Stop Watch/timer Lab packet Pencil
1) The WAVER and the HOLDER should each grab opposite ends of the slinky and carefully walk to opposite sides of the RED tape lines on the floor. (Distance = _______ meters)
2) The spotter should stand about half way between the WAVER and the HOLDER.
3) Place the Slinky of the floor holding onto it securely to make sure it does not slip and rocket back to the WAVER.
4) Once the HOLDER and WAVER are in place, the timer should count down, 3-2-1-GO and start the timer. 5) On go, the WAVER should move their hand quickly forward and back trying to produce one single compression using a LOW amount of force.
6) The spotter should observe the wave as it moves past them and identify how many times the wave bounces back and forth before stopping.
7) Record the number of bounces in your data table.
8) Record the time it took for the wave to go from the WAVER to the HOLDER in your data table. (Be precise) 9) Repeat steps 5-7, but this time use MEDIUM force. In your last test, try to use a HIGH amount of force. 10) Calculate the SPEED of your waves by using the formula (speed = distance/time)
Team Member’s Name Time
(sec)
Speed
(m/sec)
Number of Wave Bounces
Low force= Medium force = High force= Low force= Medium force = High force= Low force= Medium force = High force= Low force= Medium force = High force=
Data Table
Analysis and Conclusion questions:
Directions: Complete the following questions using your observations from the lab and the knowledge you have gained through our class discussions. Your responses MUST BE TYPED and in COMPLETE SENTENCES! 1) How does the number of “wave bounces” coincide with the force you exerted into your waves?
2) What does the SPEEDand SIZE of the compressions have to do with the amount of force you put into the Slinky?
3) What did you notice about the size and power of your waves after they bounced off the holder. 4) Describe the amount of energy you felt hitting, as the holder, during each wave test.
Part 3 – Snake-Spring Wave Test
In this test you will working to determine the FREQUENCY and WAVELENGTH of your
snake-spring waves.
Materials
:Snake-spring Stop Watch/timer Lab packet Pencil
1) The WAVER and the HOLDER should each grab opposite ends of the slinky and carefully walk to opposite sides of the WHITE tape lines on the floor. (Distance = _____ meters)
2) The spotter should stand about half way between the WAVER and the HOLDER.
3) Place the Snake-spring of the floor holding onto it securely to make sure it does not slip and rocket back to the WAVER.
4) Once the HOLDER and WAVER are in place, the timer should count down, 3-2-1-GO, and start the timer. 5) On go, the WAVER will move their hand from left to right for 5 seconds to produce an ongoing transverse wave with a LOW frequency.
6) During this time, the spotter should observe the wave as it moves past them and count the number of crests.
7) Record the number of waves the spotter counted in your data table.
9) Repeat steps 5-7, but this time try to produce a wave with a MEDIUM frequency. In your last test, try to produce a wave with a HIGH frequency.
**(Your hand MUST cross over at least two floor tiles when producing all of your waves)** 10) Calculate the ACTUAL FREQUENCY of your waves by using the formula:
(FREQUENCY = number of waves/second) **unit = Hertz (Hz)**
Data Table
Team Member’s Name Number of Waves Actual Frequency
(number of waves per second)
Wavelength
(Short, Medium, Long)
Low = Medium = High = Low = Medium = High = Low = Medium = High = Low = Medium = High =
Conclusion questions:
Directions: Complete the following questions using your observations from the lab and the knowledge you have gained through our class discussions. Your responses MUST BE TYPED and in COMPLETE SENTENCES! 1) What did you have to do with the snake-spring to get the highest frequency wave?
2) Describe the amount of energy you needed to use to create your high frequency wave compared to the amount of energy needed to create a low frequency wave.
3) What did you notice about the wavelength and frequency of your waves during the experiment? Does your data and calculations support this claim? Explain.
