How do you measure the speed of sound? It s going to be simple! Come on! I m in a hurry!

Method 1. Method 1: After a sound is generated, it does not reach your ears immediately, usually after a period of time.

It's hard to understand unless you have this experience yourself. For example, if you attend a sports day and sit at a distance from the person who fired the gun, you will see the gun smoke first and hear the gunfire later.

This is because light travels very fast (about 300,000 kilometers in 1 second) and sound travels much slower (about 340 meters in 1 second). So you'll see the gun smoke right away, but the sound won't be heard until a little while. �

So the early measurement of the speed of sound was an experiment with a gun. The helper was to hold a gun at a measured distance, and the other person stood at the origin with a horse's watch. After seeing the signal, the helper fired a gun into the air.

As soon as the person at the origin saw the sparks and smoke of the gun, he pressed down the horse's watch; And when he heard the gunshots, he pressed the watch again to stop him. The time between seeing a spark and hearing a gunshot is the time it takes for the sound to travel a measured distance through that segment. You can calculate the speed of the sound.

According to this principle, you might as well try it out in the future school sports day (using the 100-meter race).

Method 2: In order to measure the speed of sound, you need a horse watch and a tape measure. Measure a distance of 500 meters and be as accurate as possible.

You and your classmates stand at opposite ends; Your classmates hold a large stone in each hand (or a gong, a drum, or simply clap their hands – the clapping is too low to be heard by the other person), and you take a horse watch. When you shout "start", your classmates should lift the stone above their heads and hit it as loud as possible. As soon as you see the stones crashing together, press the horse watch.

Wait until you hear the sound of the stone crashing, then press the watch again to stop it. In terms of time, it is necessary to record tenths of a second. It would be best if you could do a few more experiments to calculate the average of the time.

You can use a computer to divide the distance between you and your classmates by time to calculate the speed of sound.

Two classmates are some distance away from each other (not too short, not too long. One shouted, and motioned for another classmate to shout. When the non-shouting person sees the signal to use the stopwatch to mark the time, the sound stops listening. Remeasure the distance and calculate.

What the physics teacher said.

Find a well and measure the length (tie a stone to the rope, put the rope into the well, and measure the length of the rope).

Then shout at the well (cat meow is OK, the teacher said) and press the stopwatch at the same time, stop when you hear an echo, and divide the time by 2 to get the time t

And then we use the formula v=s t to get the speed of sound about 340m sok, which is measured with echoes.

One of the simplest and most effective ways to measure the speed of sound is to use the basic relationship between the speed of sound v, the frequency f and the wavelength, that is, a pair of ultrasonic piezoelectric ceramic transducers with the same structure (transmitter and receiver) are used to convert the sound pressure to the voltage.

The amplitude and phase of the ultrasonic wave are observed by using an oscilloscope, the wavelength is determined by the amplitude method and the phase method, and the frequency f is directly read out by the oscilloscope.

Resonant frequency: The ultrasonic piezoelectric ceramic transducer is the key component of the experiment, each pair of ultrasonic piezoelectric ceramic transducers has its own inherent resonant frequency, when the working frequency of the transducer system is in the resonant state, the ultrasonic power emitted by the transmitter is the largest, which is the best working state.

Fundamental quantities in acoustics.

In acoustics, it is the basic quantity in acoustics that describes the characteristics of a sound source and the sound field it generates, or some quantities that play a dominant role in certain acoustic phenomena and effects. Table 1 lists these fundamentals and their interrelationships. Of the first four quantities, sound intensity is the easiest to measure and can be measured very accurately, and the other three can be derived from sound intensity, so it has been mistaken in the past that only sound intensity is the fundamental quantity in acoustics.

The above content refers to: Encyclopedia - Acoustic Measurement.

Measuring tools: tape measure, horse watch, drum.

Measurement method: 1. Prepare a horse watch and a pair of tape measures for backup;

2. Use a tape measure to measure the distance of 500 meters;

3. Two people stand at both ends of the measured distance;

4. One person holds a drum and one person holds a horse watch;

5. The person holding the horse watch shouts the command "start", and the other person beats the drum in his hand;

6. When observing the action of the person beating the drum, press the horse watch to record the time, and when you hear the beating drum, you will record the time according to the date of dismounting again;

7. According to the recorded data, the speed of sound can be calculated by dividing the distance by the meter of time.

After finding the frequency of the ultrasonic wave (that is, the resonant frequency of the transducer), the speed of sound can be obtained by measuring the wavelength of the signal. We use the standing wave method and the phase comparison method to measure the signal wavelength

1) Standing wave method.

After the signal generated by the signal generator passes through the ultrasonic tester, it generates a standing wave between the two transducers. When you change the distance between the transducers (move the transducer on the right), the amplitude of the signal at the receiving end (the transducer that converts the acoustic signal into an electrical signal) changes accordingly. When the distance between the transducers is half the wavelength of the signal, the amplitude of the signal at the receiving end is the maximum.

In the experiment, adjust the oscilloscope's vertical mode selector switch, trigger source selector switch, internal trigger source selector switch, auto-norm-x-y switch, so that the receiver signal is displayed on the screen, see the "use and adjustment of oscilloscope" section in the previous "adjustment instrument". Then, while moving the right transducer, observe the amplitude of the signal on the oscilloscope.

When the signal amplitude is maximum, the distance between the transducers is read out by means of an amplified vernier caliper. When the amplitude of two adjacent signals is maximum, the distance difference between the transducers is half the wavelength. In this way, the wavelength of the sound wave is known, and the frequency of the signal is read from the signal generator, so that the speed of sound can be calculated according to the formula for calculating the speed of sound.

(2) Phase comparison method.

Due to the distance between the two transducers, there is a phase difference in the signal at the two transducers. When the distance between the transducers changes by one wavelength, the phase difference changes by 2pi.

In the experiment, the oscilloscope's vertical selector switch, trigger source selector switch, internal trigger source selector switch, and auto-norm-x-y switch were adjusted, so that the Lisa Ru diagram of the signal generated by the two transducer terminals was displayed on the screen (see Fig. 4 Lisa Ru image). Then, while moving the transducer on the right, observe the Li Saru on the oscilloscope.

When a 2pi change in the phase difference between the two signals is observed, the distance between the transducers at this point is read out by means of an amplified vernier caliper. The wavelength of the sound wave can be obtained by means of a vernier caliper, and the frequency of the signal can be read out from the signal generator, so that the speed of sound can be calculated according to the formula for calculating the speed of sound.

A vibrating object can emit sound, and the sound emitted by an object can only be propagated to the surroundings by a medium, and the speed at which the sound propagates is different for different media. So, let's design an experiment to measure it together. Experiment 1:

Measuring the speed of sound in the air Equipment: meter ruler (or tape measure) stop table Steps: 1

Stand in an appropriate position in front of a high wall (outdoors) and be able to hear a clear echo as you clap your hands, and your partner will measure your distance to the wall with a ruler. 2.Clap your hands vigorously and then when you hear an echo.

Practice a few times so that the clapping sound and echo are in harmony. 3.Clap continuously for ro times, the partner notes the time of clapping for lo times, and finds the average interval between each adjacent clap (reduce the measurement error, the same below).

4.Divide 2 times your distance from the wall (the distance the sound travels when you hear an echo) by the average interval between each adjacent clapping to get the speed at which the sound travels through the air. Think:

1.How are echoes formed? What are the conditions under which an echo is generated?

2.If the speed of sound propagation in the air is 340 m s, how far away can you be from the wall?

Choose 2 locations that are slightly farther apart, measure the distance s s between them, the person at one end shoots at the same time, the person at the other end starts the timer after seeing the smoke, and stops the timer after hearing the gunshot, the time on the stopwatch is t, then the speed of sound v=s t