Speed Of Sound

• databot

• IOS/Android Smart Device

Speed of Sound

Background

What You Will Need/Prep

• Test your databot™ connection.

• You will be prompted to select
  and connect to databot™ each
  time you launch an experiment.

• If there are two or more
  databot™'s listed, the one
  closest to your device will be
  highlighted in blue.

Overview

• Install Vizeey™ on your
  Smart device.

• Study the background
  information and terms and
  prepare to explore!

Grades: Middle School

Time: 45 Minutes

Subject: Physical Science

Topics: Sound, Sound Waves, Speed
of Sound

• Slinky

• Ruler or measuring tape

• Flask or tube with water

• Thread and marker

Learning Objectives

By completing this lab, you will:

• Understand the relationship between sound, wavelength, frequency, and speed.

• Identify and explain the conditions for resonance in an air column.

• Measure and record the length of an air column that produces resonance for a given
  sound frequency.

• Use databot to detect and record changes in sound intensity as the air column length
  changes.

• Analyze patterns in the recorded data to determine the wavelength of the sound wave.

• Calculate the speed of sound.

• Visualize and interpret sound wave data using graphs to connect experimental
  observations with theoretical principles.

Amplitude: The maximum displacement of particles in the medium from their rest
position, corresponding to the loudness or intensity of the sound.

Air Column: A confined space of air, such as inside a tube, where sound waves can reflect
and create standing wave patterns.

Echo: A reflected sound wave that bounces back after hitting a surface. Used to calculate
distances and measure the speed of sound.

Frequency: The number of complete sound wave cycles passing a given point per second,
measured in hertz (Hz). Determines the pitch of the sound.

Medium: The material (e.g., air, water, metal) through which sound waves travel,
significantly influencing their speed and behavior.

Reflection: The bouncing back of sound waves when they encounter a surface or
boundary, necessary for forming standing waves in a resonating air column.

Resonance: A phenomenon where a system vibrates at maximum amplitude when the
frequency of an external force matches its natural frequency, amplifying the sound.

Sound Wave: A vibration that travels through a medium (e.g., air) as a longitudinal wave,
compressing and rarefying particles in the medium.

Speed of Sound: The rate at which sound waves propagate through a medium, dependent
on factors like the medium's density and temperature.

Wavelength: The distance between two consecutive points on a wave that are in phase
(e.g., from one compression to the next). It is related to the speed and frequency of the
wave.

Press this button to start the experiment.

• Graph showing the sound level

In order to work with the experiment you need to launch the Vizeey application and click on
+ in the upper right corner.

Then select “Add experiment from QR code” and scan the QR code prepared for this
experiment. Your experiment will appear in the list.

When you start the experiment you will be immediately
offered to connect to your databot. Make sure that databot
is turned on and in Vizeey mode with a blue blinking light.

• Sound intensity value in real-time.

This lab work investigates the intensity of
sound.

The lab work will involve generating a sound
source of different frequencies. To do this, scan
the qr code with your phone.

Set the frequency

Start the sound

What is sound, and how does it travel through different materials?

Can sound exist in a vacuum? Why or why not?

Part 1: Initial Observations and Discussion Questions

What are some examples of sound waves we can’t hear but are used in everyday life?

Based on your understanding of sound, propose a hypothesis about how the speed of
sound could be measured using a databot sound sensor. Consider what data you might
need to collect and how this data could be used to calculate the speed of sound.

Sound travels in waves, before we begin testing sounds let's look at how waves behave.

A wave is a repeating disturbance or vibration that travels through a medium or space,
transferring energy from one point to another without the permanent movement of the
medium itself. Waves can be classified based on their motion and direction of energy
transfer.

There are several types of waves, transverse and longitudinal

A great way to observe wave movement and
understand their differences is to use a long, flexible
spring or a Slinky toy

Slinky

Transverse Wave

A transverse wave is a type of wave where the particles of the medium move perpendicular
to the direction of the wave's energy propagation. An example of a transverse wave is a
wave on a string or light waves.

• Example: If the wave travels horizontally, the particles move up and down.

Part 3: Experiment Procedure

• Secure one end of the Slinky to a stable surface, such as a wall or a heavy object that
  won’t move.

• Stretch the Slinky gently to a length of 2-3 meters, ensuring it remains taut and steady.

• Wait for the Slinky to settle so it stops moving completely.

• Quickly move your hand holding the free end of the Slinky up and down in a sharp
  motion to create a wave.

What Happens.

When a wave is created, it will travel along the length of the Slinky. Once the wave reaches
the anchored end, it will reflect back and move toward you. You can observe the
continuous motion of the wave as it travels and reflects.

Transverse wave graph

Longitudinal Wave

A longitudinal wave is a type of wave where the particles of the medium move parallel to
the direction of the wave's energy propagation. Sound waves traveling through air are a
common example of longitudinal waves.

• Example: If the wave travels horizontally, the particles oscillate back and forth in the
  same direction.

Part 3: Experiment Procedure

• Secure one end of the Slinky to a stable surface, such as a wall or heavy object that will
  not move.

• Carefully stretch the Slinky to a length of 2-3 meters, making sure it remains taut and
  stable.

• Wait until the Slinky calms down and stops moving completely.

• Move your hand back and forth (in the direction of the arrows) to create a wave.

What Happens.

A longitudinal wave will form and travel through the Slinky, resembling the way sound
waves move through air. When the wave reaches the fixed end, it will reflect back toward
you. You can observe the motion of the wave as it travels, reflects, and continues to move
back and forth along the Slinky.

Wave

Part 3: Experiment Procedure

Creating Sound

Sound is produced by any vibrating object. In this experiment, we will create vibrations
with a ruler and observe how sound is produced.

Сhanging the distance you
get a different frequency and
a different sound.

What Happens.

The vibrating ruler creates sound waves, which travel through the air (an elastic medium) to
your ears. By adjusting how much of the ruler extends off the edge of the table, you can
change the frequency of the vibrations and the pitch of the sound. More ruler hanging off
the edge: Slower vibrations, lower pitch. Less ruler hanging off the edge: Faster vibrations,
higher pitch.

Sound is a sensation created in the ear when sound waves reach it. These waves are
caused by the vibrations of an object, like the ruler in this experiment. The air around the
vibrating ruler acts as the medium, allowing the waves to travel to our ears. This simple
demonstration helps to connect the concepts of vibration, sound waves, and perception of
sound.

Part 3: Experiment Procedure

Now that you understand waves and sound, you can conduct an experiment to calculate
the speed of sound using a hands-on approach. Sound waves travel at different speeds
depending on the medium they move through. For example, the speed of sound in air (at
room temperature) is approximately 343 m/s, which is what humans typically hear. In
water, sound travels faster at about 1,480 m/s, and in solids like steel, it can reach speeds
of over 5,000 m/s. These differences occur because molecules in solids and liquids are
closer together, allowing sound waves to propagate more quickly. Using this experiment,
you will focus on measuring the speed of sound in air.

Experiment: Measuring the Speed of Sound Using
Resonance in an Air Column.

Setup:

• Fill the tube partially with water, leaving some
  space for an air column above it.

• Ensure the tube is placed upright and securely
  fixed to prevent movement.

• Generate a Sound Wave:

  • Use the tone generator app on your
    smartphone to create a sound of a specific
    frequency (1000 Hz).

• Position the smartphone's speaker near the open
  end of the tube to send sound waves into the air
  column.

Objective:

To calculate the speed of sound in air using the
resonance method with an air column and databot.

• Attach the Databot to a string to safely lower it into the tube.

• Open the Vizeey app on your smart device.

• Turn on databot (using the small button on the left side)

• Tap on "Speed of Sound" in Vizeey to load the experiment.

• You will be prompted to connect to databot.

  • Hint- if there is more than one databot in use, the one closest to you will be in blue!

  • A solid blue light on databot means you are connected.

• Start your experiment using:

  • Use these icons at the top of the screen in Vizeey to start and to pause the
    experiment.

• Gradually lower the Databot into the tube, observing the graph of sound intensity.

Part 3: Experiment Procedure

• Find the Resonance Points:

Be careful when lowering databot into the water pipe.
Do not lower the device into the water. Water can
damage the device

When you've found the first resonance
point, put a marker on the thread that you
lower the databot with.

• Pull databoot out of the tube and
  measure the resonance point
  distances you marked on the thread

• Record the Resonance Points:

  • Measure the distance between consecutive resonance points (peaks).

Lower the databot to the second
resonance point and also mark it on the
thread with a marker.

Part 4: Data Analysis

The distance between two consecutive peaks corresponds to half the wavelength of the
sound wave.

You have all the data.

To calculate the speed of sound, use the formula:

=1000Hz (sound frequency)

= (wavelength) is equal to twice the distance between the peaks. ( during the
experiment I got a distance of 15.3 cm )

Now, substitute the values:

The speed of sound is 306m/s.

The speed of sound in air under standard conditions (at 20∘C) is approximately 343 m/s.

The margin of error is approximately 10.8%.

That's an excellent result.

Do some of these experiments using different audio frequencies on your phone.

Do your calculations here and record the results in the table.

Data Interpretation:

What is sound, and how does it travel through different mediums?

How are frequency, wavelength, and speed of sound related?

Why does sound travel faster in solids than in air?

Why do we see peaks and troughs in the intensity graph recorded by the databot?

1. What challenges did you face when identifying the resonant frequency during the
   experiment?

Part 6: Reflection

2. How accurately do you think the databot captured the changes in sound intensity?

3. In what ways could experimental error affect the calculation of the speed of sound?

4. If given a chance, what would you modify in this experiment to improve its precision

or efficiency?