Experiment #9: Water Cup Telephone

Water Cup Telephone Experiment is definitely a very cool experiment for the kids from 3 years. It is also a simple experiment to put together. There is share day once a week in my son's pre-school.

 

 

Kids are encouraged to bring a toy, photography or anything they feel that is worth sharing with their peers. My son would carry Dusty, Disney Plane, Crane from Bob the builder and sometimes he will do experiments. Last week he took the dollar store crystals set and show it to his friends how the gel turned into crystals. His class teacher encouraged him to do something similar. So this week we shared water cup telephone experiment with his friends.

 

 

 

When we made the water cup telephone, I let my son tie the knots. He tied it too strong that the cup tore. That's fine. Let them do,  watch and learn. Over the months, I have learned to be more patient and quiet. I let him do the talking and let him explore freely without any restrictions.

 

 

First time, we both spoke and heard each other. He tried the same with kulfi and his grandparents. After that he made me hold the cup straight and asked me not to talk. He kept the cup in his ears and with his fingers, he played with stretched twine. It created vibrations like a string instrument in his ears. He was thrilled and even I didn't think beyond talking and hearing through the cups. He now wonders how real telephone and mobile phone works.

 

 

Aim

To see whether speaking into water cup will transfer sound to the other person hearing through the water cup.

 

What you will need?

• 2 water cups (we used paper water cups)
• Kitchen twine, as per your desired length
• Safety pin or sharp pencil to punture hole
• 1 or more curious kids
• An energetic parent

Directions

1. Using a sharp pencil or safety pin, make a tiny hole on the centre of the water cup. Please make sure the hole is big enough to slide the twine. Don't make it too large.
2. Gently slide the twine through the hole and do multiple knots, large enough that the twine doesn't slide back.
3. Connect the twine to the other water cup in a similar way.
4. Hand over one end to a kid and you hold the other end.
5. IT IS IMPORTANT TO KEEP THE TWINE STRAIGHT FOR THE SOUND TO TRAVEL. It will not work if the twine is bend or falling down.

For the kids its nothing but magic. Atleast thats the case with my son. I love to watch those curious little eyes light up watching the magic of science.

 

But for adults, we need to know what actually is happening. When we speak into the cup, sound waves travel from one end to another. When they travel, they are converted into vibrations at the bottom of the cup. The sound waves dance its way in the form of vibrations to the cup at the other end. In this case, twine is the medium that transports it. When it touches the bottom of the second cup, they are converted back into sound waves. That is how the second person at the other end hears what the first person said. We all know that sound travels through air but it travels even better through solid medium allowing us to hear the sounds.

Experiment #8: Soap Bubbles

Soap bubbles are interesting for everyone. My 18 months old girl loves it, my 4.5 years old boy loves and I love it too. Yesterday my mother-in-law was busy cooking an awesome Tamil Nadu meal of Mutton Biryani, Mutton Curry, and Rasam. On Saturday we went to Hidden Villa, Los Altos. I have shared details in this post.

Since I had the time, I decided to spent it with my kids. We were snacking on pistachios and saved its shells to make art work. We will reveal it next week as he needs to paint the dried shell. We made a greeting card with it.

 

After that we did an experiment with soap bubbles. Water excites my son. He loves to play with it all the time. Yesterday we used water, soap and straw to make bubble mountains. When air is blown through straw into a container, cascades of bubbles are created which rises high and falls over the rim.

 

 

 

What is the science behind bubble?
In our case, I had the opportunity to talk about shapes and light. For older kids, we can talk about surface tension, geometry and chemistry. For pre-schoolers like my son, this experiment will help them investigate, discover and explore the world of magical bubbles.

 

What is a bubble?

 

A bubble is nothing but air wrapped in soap film. It is made of soap molecules. The bubbles always take a sphere shape because that has the smallest surface area for the amount of volume. When you blow, bubbles stretch and takes all crazy shape. Once its sealed and release into the air, the tension in the bubble skin shrinks to the smaller shape for the volume of air that got trapped inside it.

 

What you need?

• 8oz plastic tumbler
• Few drops of dishwashing soap
• Straw
• Happy kid who loves bubbles
• Kitchen Sink or Bathtub or Patio or Backyard

How to do it?

1. Add water to fill half of the tumbler. Add few drops of dishwashing liquid. Stir with the straw.
2. Ask the child to blow air through the starw so bubbles start emerging on the surface. Let the child to make a tall mountain.
3. Repeat and let the child have fun

As he made the bubbles, I asked him the following questions.

1. What is the shape of the bubbles?
2. What colors do you see?
3. How high can he make the bubble fountain?

 

My 18 month old daughter stood next to him and kept popping the bubbles. She enjoyed it too.

 

 

 

Have you noticed that bubbles pop even without being touched or poked?

That is because they pop when the water between the soap film surface evaporates.

 

We did the experiment in the kitchen sink. There is a window right above the sink. The sun rays fell on the bubble and gave a prism effect. Katli was excited to see rainbow colors in the bubbles. A buble gets it color from light waves reflecting between the soap film. Bubbles can also reflect whats around them like the faces around them.

 

In the picture, you can see that the bubbles got the hexagon shape. It looked like beehive. When bubbles are about the same size, they form perfect hexagons. My son has always seen only bubbles that are round and so this was something new for him.

 

 

Experiment #7: Volcano Effect with Baking Soda and Vinegar

I feel terrible that I have neglected this space for quite sometime. Life has been getting busy and my kids are growing up fast. Katli is 4 + years old now and when I started this blog more than a year ago, he was that tiny, timid boy. Now he has grown to a pre-KG student who walks around with his curious eyes and lots of questions in mind. We have been doing science experiments from simple kitchen ingredients every Wednesday. We are also busy testing recipes for my pop-up dinners in San Francisco and San Mateo. My next one is on 07Mar2015 and I am hosting this meal to celebrate  International Women's Day. Yes, we dedicated one day in a week for mini science projects. I am sure that every kitchen will carry baking soda and vinegar. So I planned the experiment using it. We have already done an experiment with the exact same concept here.

 

 

 

Aim: To create volcano effect in the kitchen using baking soda and vinegar

Things needed: 

1. 1 small empty glass tumbler  or plastic bottle
2. 3-4 tablespoon baking soda
3. 1/2 cup vinegar
4. Play Dough (any color)
5. Larger container to prevent spilling
6. Kitchen tissues to clean

Directions:

1. Let the child cover the container with play dough or you can use a small plastic bottle and create a mountain with brown coloured play dough. 
2. Place it over a bowl. This will catch the excess vinegar that will overflow.
3. Ask the child to add few spoons of baking soda to the glass/plastic container. 
4. Gently pour the vinegar and watch the fizz.
5. Pour the vinegar in batches to create a volcano effect.

 

 

What actually happens?

It is a simple acid-base reaction. When baking soda and vinegar comes in contact they react to produce carbon dioxide. The gas spreads out and reaches the top and overflows with a fizz. 

I explained in a much simpler way to my four year old son. I said when this white powder touches the vinegar, magic happens. I told him to watch the fizz and see how bubbles reach the rim of the containers and spills over. He loved it and we repeated the experiment thrice. Yes, practice and repetition is key.

 

 

Experiment #6: Does clementine/ orange float or sink in water?

Katli and I are back with another experiment after a short hiatus. I started work in February after the maternity time off. It took us sometime to adjust to a schedule and finally we are here to share an experiment with our favourite ingredient - WATER. Yes my son loves to play with water.

Yesterday we were at my friend's place to celebrate Holi (Indian festival that is celebrated with colors to welcome Spring). The kids enjoyed the most as we let them play with water. On the drive back home, I asked my son the name of the festival he celebrated. His reply was "Splish Splash Festival". He didn't remember the word - Holi but all he recollected from yesterday's party was having fun with water.

Coming to our experiment, let me tell you what we have for you today. We enjoyed eating a lot of clementines/oranges since February. So I planned an experiment with clemetines, green grapes and potatoes.

Aim

To see whether clemetines, grapes and potatoes float or sink in water

Things Needed

• Couple of clementines or orange
• Few green grapes
• Couple of potatoes
• A deep container / bowl filled with water

Directions

1. Prepare the working area. Make sure it can stand all the water spills. I do the experiments in kitchen island. Fill the bowl with water.
2. Put the orange in the water and watch what happens.
3. Put the grapes in the water and watch what happens.
4. Put the potatoes in the water and watch what happens.
5. Peel the rind from the orange and try the experiment again, ask the kid what he/she sees.

What actually happens?

When you put the orange in the bowl of water it floated on the surface. But after you removed the rind,it sinks to the bottom. But that was not the case with green grapes or apple, they sink to the bottom all the time.

The rind of an orange is made of tiny air pockets . When placed in water, they float as the air pockets give it a lower density than water. So when rind is removed, all the air pockets are gone. The orange now sinks as its density is higher than that of water.

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