Can you hear the sound of a drum?
This question stayed unanswered for a quarter of a century, until in 1992 mathematicians gave an example of two differently shaped drums that sound exactly the same. The answer to Kac’s question is therefore “No, you cannot always hear the shape of a drum”.
What vibrates in a drum to make a sound?
Sound is created by a vibrating object. For example, when a drum is struck, the flexible skin (sometimes called a membrane) of the drum vibrates. The compression and expansion of the air on either side of the vibrating membrane produces differences in air pressure.
How does a drum set work?
Striking the head of the drum changes its shape and compresses the air inside the shell. The compressed air presses on the bottom head and changes its shape. Then, these changes are transmitted to the drum shell and reflected back, and this action is repeated, creating a vibration.
How do sound travels through air?
When a drum is hit, the air particles next to the drum skin vibrate and collide with other particles, and this vibration is then transmitted through the air. This is known as wave compression, which allows sound to travel quickly through the air.
What does sound travel through the slowest?
gases
Does sound travel faster in water or air?
While sound moves at a much faster speed in the water than in air , the distance that sound waves travel is primarily dependent upon ocean temperature and pressure.
Why can’t humans hear underwater?
The sound waves don’t move through the air, they move through the water. Sound waves actually travel five times faster in water than in air. Underwater those sound waves don’t vibrate the ossicles bones in your inner ear. They go straight to the skull bones, vibrating that heavy bone you can touch just behind your ear.
Is sound louder in water or air?
Sound travels faster in water compared with air because water particles are packed in more densely. Thus, the energy the sound waves carry is transported faster. This should make the sound appear louder.
Why is it so quiet after a snowfall?
But there’s science behind the silence as well. That’s because snow absorbs sound, so when a fresh blanket of snow covers the landscape it absorbs many of the sound waves, making it seem quieter outside, according to AccuWeather. Those spaces absorb sound waves, creating a quieting effect over a blanket of snow.
Why is it so quiet at night?
You may wonder, it is because it is quieter at night than in the daytime. Actually, sound transmits farther at night may be related to refraction of sound waves! First, sound is the vibration of air, and it is a kind of wave motion. The propagation of sound wave is faster in hot air and slower in cold air.
Does snow really absorb sound?
Snow and sound When the ground has a thick layer of fresh, fluffy snow, sound waves are readily absorbed at the snow surface, dampening sound. However, time and weather conditions may change the snow surface.
What makes sound when two things collide?
The fact that sound is a form of energy is most obvious when two objects collide; they lose some of their mechanical energy to sound (in the form of a crash). Likewise, when the surfaces of two objects scrape together, friction makes the molecules vibrate, which creates the pressure waves that produce sound.
What is the sound of a collision?
When a leaf falls to the ground, the impact injects relatively little energy into the surrounding air molecules, so the molecules don’t move much. But when two hefty, fast-moving objects collide, the noise can literally be deafening.
How do you make a sound when you speak or sing?
How do we create sound with our voices? The vocal folds sit at the top of the airway. During exhalation the vocal folds come together and vibrate, interrupting the air flow. However many times the folds vibrate per second is the pitch being sung.