Sound Flashcards
What the equipment utilised for the practical investigating the Speed of sound?
Trundle Wheel, wooden blocks, stopwatch, oscilloscope, 2 microphones and a tape measure.
What is the purpose of trundle wheel in the practical investigating the speed of sound?
To measure the distance travelled by the sound waves.
What is the purpose of wooden blocks in the practical investigating the speed of sound?
To create a sound by banging together.
What is the purpose of the stopwatch in the practical investigating the speed of sound?
To time how long it takes the sound waves to travel.
What is the purpose of the oscilloscope in the practical investigating the speed of sound?
To display the sound wave electronically.
What is the purpose of the two microphones in the practical investigating the speed of sound?
To detect sound waves and turn them into an electric signal.
What is the purpose of the tape measure in the practical investigating the speed of sound?
To measure the distance between microphones.
What are the two experiment to investigate the speed of sound?
Experiment 1: Measuring the Speed of Sound Between Two Points with a stopwatch
Experiment 2: Measuring the Speed of Sound with Oscilloscopes
What is the aim of the experiment: Measuring the Speed of Sound Between Two Points (with a stopwatch)?
The aim of this experiment is to measure the speed of sound in air between two points.
What is the independent variable of the experiment: measuring the speed of sound between two points (with a stopwatch)?
Independent variable = Distance
What is the dependent variable of the experiment: measuring the speed of sound between two points (with a stopwatch)?
Dependent variable = Time
What is the control variable of the experiment: measuring the speed of sound between two points (with a stopwatch)?
Control variables:
Same location to carry out the experiment
What is the method for the experiment: measuring the speed of sound between two points? (using a stopwatch)
- Use the trundle wheel to measure a distance of 100 m between two people
- One of the people should have two wooden blocks, which they will bang together above their head to generate sound waves
- The second person should have a stopwatch which they start when they see the first person banging the blocks together and stop when they hear the sound
- This should be repeated severa times and an averade taken for the time travelled ov the sound
waves - Repeat this experiment for various distances
- Make a table of results
What is the equation for average speed?
Average speed = Distance moved/Time Take
What is the speed of sound in air?
The speed of sound in air should work out to be about 340 m/a.
What is the aim of the experiment: measuring the speed of sound with oscilloscopes?
The aim of this experiment is to measure the speed of sound in air between two points using an oscilloscope.
What is the independent variable for the experiment: measuring the speed of sound with oscilloscope?
Independent variable = Distance
What is the depedent variable for the experiment: measuring the speed of sound with oscilloscopes?
Dependent variable = Time
What are the control variables for the experiment: measuring the speed of sound with oscilloscopes?
Control variables:
- Same location to carry out the experiment
- Same set of microphones for each trial
Describe the method for the experiment to measure the speed of sound with oscilloscopes
- Connect two microphones to an oscilloscope
- Place them about 2 m apart using a tape measure to measure the distance between them
- Set up the oscilloscope so that it triggers when the first microphone detects a sound, and adjust the time base so that the sound arriving at both microphones can be seen on the screen
- Make a large clap using the two wooden blocks next to the first microphone
- Use the oscilloscope to determine the time at which the clap reaches each microphone and the time difference between them
- Repeat this experiment for several distances
- Make a table of results
What is the systematic error in the experiment: measuring the speed of sound with oscilloscopes and what is the solution?
The scale is likely to be small (e.g. milliseconds) so ensure this is taken into account when calculating speed. Solution: Ensure the scale of the time base is accounted for correctly
What is the random error in the experiment: measuring the sound of speed between two points (with an oscilloscope) and what are the solutions?
A main cause of error in Experiment 1 is the measurement of time
Ensure to take repeat readings when timing intervals and calculate an average to keep this error to a minimum
Maximise the distance between the two people where possible. This will reduce the error in measurements of time because the time taken by the sound waves to travel will be greater
What is an oscilloscope?
An oscilloscope is a device that can be used to study a rapidly changing signal, such as: a sound wave and an alternating current
What is the time base (the ‘x-axis’) is used to measure on an oscilloscope?
The time base (the ‘x-axis’) is used to measure the time period of the wave
What is the height of the wave on an oscilloscope related to?
The height of the wave is related to the amplitude of the sound.
What is the aim of the experiment: using an oscilloscope and a tuning fork?
The aim of this experiment is to investigate the frequency of a sound wave using an oscilloscope.
What is the independent variable in the experiment: using an oscilloscope and a tuning fork?
Independent variable = Tuning forks of different frequencies.
What is the dependent variable in the experiment: using an oscilloscope and a tuning fork?
Dependent variable = Time period.
What are the equipment used in the experiment: using an oscilloscope and a tuning fork?
5 tuning forks, microphones, oscilloscope and wires.
What is the purpose of the 5 tuning forks used in the experiment: using an oscilloscope and a tuning fork?
To generate sound waves of different frequencies.
What is the purpose of the microphone used in the experiment: using an oscilloscope and a tuning fork?
To detect sound waves from the tuning fork
What is the purpose of the oscilloscope used in the experiment: using an oscilloscope and a tuning fork?
To display the sound waves electronically.
What is the purpose of the wires used in the experiment: using an oscilloscope and a tuning fork?
To connect the microphone to the oscilloscope
What is the method for the experiment: using an oscilloscope and a tuning fork?
- Connect the microphone to the oscilloscope as shown in the image above
- Test the microphone displays a signal by humming
- Adjust the time base of the oscilloscope until the signal fits on the screen - ensure that multiple complete waves can be seen
- Strike the tuning fork on the edge of a hard surface to generate sound waves of a pure frequency
- Hold the tuning fork near to the microphone and observe the sound wave on the oscilloscope screen
- Freeze the image on the oscilloscope screen, or take a picture of it
- Measure and record the time period of the wave signal on the screen by counting the number of divisions for one complete wave cycle
- Repeat steps 4-6 for a variety of tuning forks
- Make a table of results
What is the systematic error in the experiment: using an oscilloscope and a tuning fork and what is the solution?
The scale is likely to be small (e.g. milliseconds) so ensure this is taken into account when calculating the time period.
Solution: Ensure the scale of the time base is accounted for correctly.
What is the random error in the experiment: using an oscilloscope and a tuning fork and what is the solution?
A cause of random error in this experiment is noise in the environment
Solution: Ensure it is carried out in a quiet location
What is the pitch of sound waves related to?
The pitch of a sound is related to the frequency of the vibrating source of sound waves.
What does it mean if the frequency of vibration is high?
If the frequency of vibration is high, the sound wave has a high pitch.
What does it mean if the frequency of vibration is low?
If the frequency of vibration is low, the sound wave has a low pitch.
What does the loudness of a sound is relate to?
The loudness of a sound is related to the amplitude of the vibrating source of sound waves.
What does it mean if a sound is loud?
If the sound is loud, the sound wave has a large amplitude
What does it mean if a sound is quiet?
If the sound is loud, the sound wave has a small amplitude.
What is the frequency range for human hearing?
The frequency range for human hearing is 20 Hz to 20 000 Hz
What is sound below 20 Hz known as?
Sound below 20 Hz is known as infrared
What is sound above 20,000 Hz known as?
Sound above 20,000 Hz is known as ultraviolet.
What state of matter will sound travel the fastest in?
Sound will travel fastest in a solid, as the particles are closest together. Sound waves must be transmitted through vibrations of particles within a medium.
What state of matter will sound travel the slowest in?
Sound will travel slowest in a gas, as the particles are the most further apart together. Sound waves must be transmitted through vibrations of particles within a medium..
What happens when sound gets reflected off a surface?
When sound gets reflected off a surface, it generates an echo.
