Lab
Speed of a Wave Along a Spring
Printer Friendly Version
Equipment
In this lab you will need several stop watches, one long spring, one 20-N spring scale, meter sticks for measuring as well as 2-loop makers, 3-loop markers, 4-loop markers.
Attach one end of your long spring to a table by slipping it over the pole of a well-secured ring stand.
Part I - 20 foot separation
Stretch the spring approximately 20 feet, which equals 6.1 meters. Remember that each floor tile is 1 ft
^{2}
. Use a 20-N spring scale to measure the tension in the spring. Do NOT move from this position until Part I of the experiment is finished.
What was the tension on your spring scale?
Send a LARGE amplitude horizontal pulse down the spring. Record the time for it to make three complete vibrations or trips. Time a total of three pulses. Record your values in the table below.
pulse trial
time (sec)
1
2
3
What was the average time for the pulse to make three complete vibrations?
Calculate the speed of the pulse along the spring using the equation
d = rt
where
d = 6(6.1) meters
and
t
is your
average time
for three complete trips recorded above.
When a periodic wave is sent down a spring, special frequencies produce loops, or regions of constructive and destructive interference. A loop equals one-half of a wavelength, ½
l
.
We are now going to vibrate the spring at three different frequencies: the first one will produce two loops, the second one will produce three loops, and the fourth one will produce 4 loops.
Each time the desired pattern is produced, we will place meter sticks on the floor under two adjacent nodes. Nodes are easily identified as locations where there is NO amplitude - where the wave form seems to stay squeezed together.
Next we will time 5 complete vibrations of the spring while maintaining
two loops
. Record your times in the table below.
2-loop trial
time (sec)
1
2
3
What was the length of a single loop when there are two loops along the spring?
What was the average time for your spring to make 5 complete vibrations when two loops were on the spring?
Next we will time 5 complete vibrations of the spring while maintaining
three loops
. Record your times in the table below.
3-loop trial
time (sec)
1
2
3
What was the length of a single loop when there are three loops along the spring?
What was the average time for your spring to make 5 complete vibrations when three loops were on the spring?
Next we will time 5 complete vibrations of the spring while maintaining
four loops
. Record your times in the table below.
4-loop trial
time (sec)
1
2
3
What was the length of a single loop when there are four loops along the spring?
What was the average time for your spring to make 5 complete vibrations when four loops were on the spring?
Part II - Doubling the Tension
Stretch the spring approximately 31.5 feet, which equals 9.6 meters. Remember that each floor tile is 1 ft
^{2}
. Use a 20-N spring scale to measure the tension in the spring. Do NOT move from this position until Part II of the experiment is finished.
What was the tension on your spring scale?
Send a LARGE amplitude horizontal pulse down the spring. Record the time for it to make three complete vibrations or trips. Time a total of three pulses. Record your values in the table below.
pulse trial
time (sec)
1
2
3
What was the average time for the pulse to make three complete vibrations?
Calculate the wave speed in the spring using the equation
d = rt
where
d = 6(9.6) meters
and
t
is your
average time
for three complete trips recorded above.
Next we will time 5 complete vibrations of the spring while maintaining
two loops
. Record your times in the table below.
2-loop trial
time (sec)
1
2
3
What was the length of a single loop when there are two loops along the spring?
What was the average time for your spring to make 5 complete vibrations when two loops were on the spring?
Next we will time 5 complete vibrations of the spring while maintaining
three loops
. Record your times in the table below.
3-loop trial
time (sec)
1
2
3
What was the length of a single loop when there are three loops along the spring?
What was the average time for your spring to make 5 complete vibrations when three loops were on the spring?
Next we will time 5 complete vibrations of the spring while maintaining
four loops
. Record your times in the table below.
4-loop trial
time (sec)
1
2
3
What was the length of a single loop when there are four loops along the spring?
What was the average time for your spring to make 5 complete vibrations when four loops were on the spring?
Calculations
Part I:
loops
frequency
(hz)
loop length
(m)
wavelength
(m)
wave speed
(m/sec)
2
3
4
Part II:
loops
frequency
(hz)
loop length
(m)
wavelength
(m)
wave speed
(m/sec)
2
3
4
Conclusions
1. What was the average wave speed in Part I when 2, 3, and 4 loops were maintained on the spring? (Chart I)
2. Calculate the percent difference between the speed of the pulse in Part I (20 foot separation) and the average wave speed from Chart I.
3. What was the average wave speed in Part II when 2, 3, and 4 loops were maintained on the spring? (Chart II)
4. Calculate the percent difference between the speed of the pulse in Part II (doubling the tension) and the average wave speed from Chart II.
5. Calculate the ratio of the average wave speed in Part I (question #1) and in Part II (question #2).
Fill in the blanks in the last three questions with one of the following terms: decreases, remains the same, increases, smaller, larger
6. In the same medium (20-foot separation or doubling the tension) the wave speed ______
8. As the tension in a spring increases, the wave speed _______.
7. In a given medium (either a 20-foot separation or doubling the tension), as the frequency increases, the wavelength ______ as shown by a _______ loop length.
Related Documents
Lab:
Labs -
Directions: Constructive and Destructive Interference
Labs -
Doppler Effect: Source Moving
Labs -
Frequency of Vibrating Strings
Labs -
Illuminance by a Light Source
Labs -
Inertial Mass
Labs -
Interference Shading
Labs -
Pipe Music
Labs -
Relationship Between Tension in a String and Wave Speed
Labs -
Relationship Between Tension in a String and Wave Speed Along the String
Labs -
Ripple Tank Checklists
Labs -
Ripple Tank Checklists
Labs -
Ripple Tank Sample Solutions
Labs -
Ripple Tank Student Involvement Sheet
Labs -
Simple Pendulums: Class Data
Labs -
Simple Pendulums: LabPro Data
Labs -
Speed of Sound in Air
Labs -
Speed of Sound in Copper
Labs -
Video: Law of Reflection
Labs -
Video: Law of Reflection Sample Diagram
Resource Lesson:
RL -
Barrier Waves, Bow Waves, and Shock Waves
RL -
Beats: An Example of Interference
RL -
Interference of Waves
RL -
Interference: In-phase Sound Sources
RL -
Introduction to Sound
RL -
Law of Reflection
RL -
Physical Optics - Thin Film Interference
RL -
Resonance in Pipes
RL -
Resonance in Strings
RL -
Ripple Tank Video Guides
RL -
SHM Equations
RL -
Simple Harmonic Motion
RL -
Sound Level Intensity
RL -
Speed of Waves Along a String
RL -
The Doppler Effect
RL -
Vibrating Systems - Simple Pendulums
RL -
Vibration Graphs
RL -
Wave Fundamentals
RL -
Waveform vs Vibration Graphs
REV -
Orbitals
Review:
REV -
Chapter 26: Sound
REV -
Honors Review: Waves and Introductory Skills
REV -
Physics I Review: Waves and Introductory Skills
REV -
Sound
REV -
Waves and Sound
REV -
Waves and Sound
Worksheet:
APP -
Echo Chamber
APP -
The Dog-Eared Page
CP -
Light Properties
CP -
Reflection
CP -
Shock Waves
CP -
Sound
CP -
Waves and Vibrations
NT -
Apparent Depth
NT -
Atmospheric Refraction
NT -
Concert
NT -
Light vs Sound Waves
NT -
Shock Cone
NT -
Sound Waves
NT -
Standing Waves
WS -
Beats
WS -
Beats, Doppler, Resonance Pipes, and Sound Intensity
WS -
Counting Vibrations and Calculating Frequency/Period
WS -
Doppler - A Challenge Problem
WS -
Doppler Effect
WS -
Fixed and Free-end Reflections
WS -
Fundamental Wave Terms
WS -
Illuminance 1
WS -
Illuminance 2
WS -
Interference: In-phase Sound Sources
WS -
Lab Discussion: Inertial and Gravitational Mass
WS -
More Practice with Resonance in Pipes
WS -
More Practice with the Doppler Practice
WS -
Practice with Resonance in Pipes
WS -
Practice with the Doppler Effect
WS -
Practice: Speed of a Wave Along a String
WS -
Pulse Superposition: Interference
WS -
Ripple Tank Review
WS -
Sound Vocabulary
WS -
Speed of Sound
WS -
Speed of Sound (Honors)
WS -
Standing Wave Patterns #1
WS -
Standing Wave Patterns #2
WS -
Standing Wave Patterns #3
WS -
Standing Wave Patterns #4
WS -
Vibrating Systems - Period and Frequency
WS -
Wave Phenomena Reading Guide
WS -
Wave Pulses
WS -
Waveform and Vibration Graphs #1
WS -
Waveform and Vibration Graphs #2
TB -
25A: Introduction to Waves and Vibrations
TB -
25B: Vibrations and Waves
TB -
25C: Wave Speed
TB -
25D: Interference
TB -
25E: Doppler
TB -
25F: Doppler Effect (continued)
TB -
26B: Speed of Sound
TB -
26C: Resonance
TB -
26D: Beats
TB -
26E: Decibels
TB -
27A: Light Properties
TB -
Decibels and Sound Intensity #1
TB -
Decibels and Sound Intensity #2
TB -
Interference Re-examined
TB -
Refraction Phenomena Reading Questions
TB -
Sound: Mixed Practice
TB -
Waves and Vibrations
PhysicsLAB
Copyright © 1997-2023
Catharine H. Colwell
All rights reserved.
Application Programmer
Mark Acton