Name: ______________________________________
Standing Transverse Waves on a Vertical Spring
Introduction:

The standing waves produced when the large coil spring was stretched across the floor and held firmly at one end (fixed-end
reflection) had nodes on both ends. When a spring is held vertically, standing waves may be produced that have a node at the
upper end and an antinode at the lower end (free-end reflection).
Purpose:

To produce standing transverse waves in a vertically held spring

To investigate the relationship between the number of loops formed and the frequency needed to generate the loops
Equipment:

stopwatches, spring
Procedure:

Stand while holding the spring with your outstretched arm. Depending on the length of the spring, you may need to cautiously
stand on a chair or table.

Begin moving the spring in small circles until a standing wave having one-half of a “loop” is formed. This standing wave will have
a node at the top of the spring and an antinode at the lower end of the spring, as seen in Figure 1.

Maintain this steady motion while two others time
your motion for ten complete cycles. Record
these time values in the data table as Trial 1.

Repeat this process and record the time values
for Trial 2 in the table.

Average all four times together and divide the
number of cycles (10) by the average time in order
to determine the frequency of the standing wave.

Repeat these steps in order to determine the
frequency of the standing wave when 1.5 and
2.5 “loops” are formed, as seen in Figures 2 and 3.

If possible, determine the frequency for 3.5 loops.
Credit: Dr. Joel Bryan, Ball State University
Figure 1: 0.5 loops
Figure 2: 1.5 loops
Figure 3: 2.5 loops
Arbor Scientific 1
Name: ______________________________________
DATA TABLE
Total Time, sec
# Loops
# Cycles
0.5
10
1.5
10
2.5
10
3.5
10
Trial 1
Stopwatch 1
Stopwatch 2
Trial 2
Stopwatch 1
Stopwatch 2
Average
Total Time
Frequency,
Hz
Questions:
1. Find the ratio of the frequency needed to generate 1.5 loops to the frequency needed for 0.5 loops by dividing the frequency for 1.5
loops by the frequency needed for 0.5 loops.
2. Since the tension in the spring remained constant, the speed of the wave in each case was the same. Use this fact and the
wavelength of the standing wave in each case to determine what the frequency comparison in question #1 should have been.
3. Calculate the % error in your experimental result.
4. Find the ratio of the frequency needed to generate 2.5 loops to the frequency needed for 0.5 loops.
Credit: Dr. Joel Bryan, Ball State University
Arbor Scientific 2
Name: ______________________________________
5. Since the tension in the spring remained constant, the speed of the wave in each case was the same. Use this fact and the
wavelength of the standing wave in each case to determine what the frequency comparison in question #4 should have been.
6. Calculate the % error in your experimental result.
7. Find the ratio of the frequency needed to generate 2.5 loops to the frequency needed for 1.5 loops.
8. Since the tension in the spring remained constant, the speed of the wave in each case was the same. Use this fact and the
wavelength of the standing wave in each case to determine what the frequency comparison in question #7 should have been.
9. Calculate the % error in your experimental result.
10. What sources of error were present in this activity?
Credit: Dr. Joel Bryan, Ball State University
Arbor Scientific 3