The same cup is filled with different amounts of water and played: the amount of water will affect the frequency of sound.

different notes can be played by tapping with different cups. This is because the size and shape of the cup and the amount of water contained in it will affect the frequency of sound. The size and shape of the cup will affect the frequency of sound.

smaller cups usually make a higher sound, while larger cups usually make a lower sound. When the cup is filled with water, the quality of the water will change the vibration frequency of the cup, thus changing the tone of the sound. Therefore, if different cups are filled with different amounts of water, different notes can be struck and different tunes can be played.

when knocking, the vibration of the cup will produce sound. If the cup is filled with water, the vibration mass will increase, and the vibration frequency will decrease, resulting in a lower tone of the sound. If there is less water in the cup and the vibration mass is smaller, the vibration frequency will be higher, resulting in a higher tone of the sound.

Frequency has important applications in many fields

1. Communication: In electrical communication, the application of frequency is very important, and information can be transmitted by adjusting the frequency of signals. For example, the signal transmission in cellular network is to realize efficient data transmission by fine control of frequency.

2. Sound: The vibration frequency of the sound we hear determines the pitch. The higher the frequency, the higher the pitch; The lower the frequency, the lower the pitch.

3. optics: in optics, the color of light is related to frequency. The higher the frequency, the shorter the wavelength of light, and the more the color tends to be blue; The lower the frequency, the longer the wavelength of light, and the more the color tends to be red.