Are you ready to spend the summer with your kids? Help students tell their own stories with free hands-on science and engineering activities to make this summer even more creative and fun.
The following STEAM activities encourage children to create and tell their own stories in innovative ways. Through these simple and creative STEAM activities, kids can have fun making things that involve scientific principles, and then they can tell their own stories and engage in imaginative games.
Frosting that dances in the sound
1. Introduction
Some superheroes can control sound with sound wave explosions, high-pitched noise, and various forms of sound waves. Think of Banshee and Siryn, Black Canary and others in X-Men! In this activity, children can explore how sound waves vibrate.
Sound is produced by vibration, but did you know that sound can also make objects vibrate? If you're in a concert hall or in a car playing stereo, you might notice. Sometimes the sound is so loud that you can feel the vibrations! However, too loud a sound can hurt your ears, and at this event, you'll explore sound in a safer way.
Duration: 20 to 30 minutes
Core concept: sound, vibration
2. Royalties
material:
Cup or bowl
rubber band
Plastic packaging film
Colored frosting (salt can also be used, but frosting is more intuitive)
Large plates or trays
3. Preparatory work
1. Cover the top of the bowl with plastic wrapping film
2. Firmly fix the plastic packaging film with a rubber band
3. Adjust the plastic packaging film to make sure it is tightly fixed and there is no wrinkle on the surface
4. Place the bowl on a plate or tray so that excess frosting falls on top.
Fourth, the steps
1. Bring your lips close to the edge of the bowl, but do not touch it
2. Try humming loudly and observe the plastic packaging film up close
Question: What happened? See something?
3. Add the icing sugar on top of the bowl
4. Hum again and observe the frosting carefully
5. If nothing happens, try humming louder
6. If you still don't move, try to hum louder and smaller for a while
7. If the icing falls, add more icing
Ask: What happens if you stop humming?
What happened?
Is frosting dancing? When you hum a song at the appropriate volume and pitch, the sound waves generated by your voice should vibrate the plastic film. The vibration of the plastic film itself is difficult to see. When you add frosting, the vibration of the membrane causes them to bounce up and down, so the vibrations are easier to see. Get more detailed physics knowledge in the Explore More column.
Sixth, explore more
1. Deep excavation
Have you ever heard an old riddle?" If a tree in the forest falls and no one hears it, will it make noise? If you know what sound waves are all about, then the answer is simple. Sound is produced by vibrating animal bodies hitting molecules in neighboring air. These air molecules collide with nearby air molecules and transmit vibrations through the air to our ears. Sometimes these vibrations are easy to see (e.g., when you play a rubber band), but most of the time the vibrations are too small or too fast for us to detect easily, such as when you knock on the door, you won't notice that the door is vibrating too. The fallen tree also vibrates, even though no one around hears it.
If vibration causes sound, can sound also cause vibration? It turns out to be a two-way street, which is why we can hear the sound. You may have heard of your eardrum, which is a small membrane in your ear. Adults will warn us not to put tiny sharp things in your ears because it will damage your ears! When a vibrating air molecule hits the eardrum, they cause the eardrum inside the ear to vibrate, and these vibrations are converted into electrical signals that are transmitted to your brain.
In this activity, you create a membrane that resembles a tympanic membrane. Depending on the material, size, and shape of the container, you need to constantly adjust the tone of your humming to make the frosting dance. If your pitch is too high or too low, the frosting may not move at all. If your tone is just right, the frosting may bounce around wildly and even fall off the bowl. The response of objects to different tones is called the frequency response, and the unit of frequency is hertz (Hz). Human hearing is usually between 20 Hz and 20,000 Hz, 20,000 Hz, and frequencies in this range will make your eardrum vibrate. Some animals, such as dogs, can hear sounds at higher frequencies, reaching 45,000 hertz. Their ear eardrum is more sensitive to high-frequency vibrations than humans, which is why dogs can hear "dog whistles" and we can't.
2. Further exploration
Do this activity with granular materials of different sizes, such as with spherical or oval frosting? What if salt and grains of rice are used?
Try using containers of different sizes, shapes, and materials
Place the bowl in front of the speakers and play music
Try searching for "audio generator" on an app or website with your phone and play an audio very close to the bowl. This audio can hurt your ears and can be kept small at first and gradually amplified.
Source: sciencebuddies website, translation: pumpkin
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