Category:Physics Experiments’

Sound Science

 - by KitchenPantryScientist

Get ready to make some noise! Read on to find instructions for making two simple experiments.

The sound we hear every day is energy that travels through air molecules as vibrations. In fact, you can’t hear sound in outer space, since there’s no air.

When I play my trombone, air travels from my lungs to my buzzing lips, which make vibrations inside the horn. The vibrations travel through the trombone, and the tube the vibration travel through gets longer when I extended the slide, making the sound lower. My daughter plays the violin, which, like other string instruments, can make short sounds by plucking the strings or a continuous sound with a bow that keeps them vibrating. Shortening the strings by pressing them down makes the pitch higher as the string vibrated faster.

 

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We have a “drum” in our ears called an eardrum, or tympanic membrane that picks up sound vibrations in the air and transfers those vibrations to tiny bones in the middle ear, which then move them on to our inner ear, sending a message to our brain.

You can make a model “eardrum” out of a cup, saran wrap and sugar sprinkles that jump when you make a loud noise right next to it.

It’s also fun to make two simple musical instruments: a straw “clarinet” and a kazoo from a comb and tissue paper. Use the instruments to make the sugar crystals on a model eardrum jump around!

straw "clarinets"

straw “clarinets”

Click on this  link to learn how to make straw “clarinets.”

To make comb kazoos, fold a piece of tissue paper in half the long way (see photo), place it over a comb with the teeth towards the fold, and place your lips on the tissue paper. Sing doo doo doo doo into the paper (don’t blow.) The vibrations from your voice will make the thin paper vibrate and buzz. It will tickle if you’re doing it right!

 

Homemade Robotics Kit (Holiday Gift Idea)

 - by KitchenPantryScientist

With a few simple technology and art supplies, you can put together a simple kit that lets kids design and build bristle bots, art bots and light-up creatures.

The Science Behind the Fun: Hooking an unbalanced spinning toy motor  to a brush sends vibrations through the bristles. The vibrating bristles move the brush, and anything attached to it, around on a flat surface.  Make a disc robot by attaching toothbrushes to a CD and attaching a motor, or make a drawing robot with legs made of pens.

Art Bot from “STEAM Lab for Kids” (Quarry Books 2018)

Light Up Creatures from “STEAM Lab for Kids” (Quarry Books 2018)

CD Bot from “STEAM Lab for Kids” (Quarry Books 2018)

I’ve included ideas for items to put in a kit, along with a tech supply list and photos of the robots from STEAM Lab for Kids. Use your imagination for art supplies! Pair the kit with a book, like STEAM Lab for Kids (Amazon.com), which has instructions for making bristle bots, art bots and light-up creatures, or let tech-savvy kids take the reigns and start building!

 

Homemade robotics kit- kitchenpantryscientist.com

 

LEDs, alligator clip test leads, toy motors and batteries let kids assemble simple circuits. (Supply list below photo)

tech components for robot kit- kitchenpantryscientist.com

Basic 3mm and 5mm through-hole LEDs (Art Bot, CD Bot, Light-Up Creature)

Small alligator clip test leads (Art Bot, CD Bot, Light-Up Creature)

AA battery holders (Art Bot, CD Bot )

AA batteries and 9V batteries (Art Bot, CD Bot )

9V battery clip snap-on connectors (battery snaps)  

3V coin cell batteries (Light-Up Creature)

Mini electric motor for DIY toys (1500 rpm) for Art Bot, CD Bot

(Find these supplies at your favorite bricks and mortar location, like Axman Surplus stores, or get them online at Amazon.com or another tech retailer.)

USA https://www.amazon.com Canada https://www.amazon.ca

 

Paper and plastic cups, brushes, toothbrushes, duct tape, zip-ties, and CDs all make great building supplies, and a glue gun always comes in handy.

building components for robotics kit- kitchenpantryscientist.com

Use your imagination for the art supplies.

art supplies for homemade robotics kit- kitchenpantryscientist.com

And if you’ve got a kid who likes to sew, it’s fun to add supplies to make sewable circuits!

Sewable electronics: coin cell battery holders, sewable LEDs, snaps and conductive thread  

USA https://www.sparkfun.com/lilypad_sewable_electronics and https://www.adafruit.com

Canada https://www.amazon.ca

Europe https://www.amazon.co.uk

Here are instructions for building a simple bristle bot.

Have fun!

Homemade Water Bottle Insulator (Back to School Science)

 - by KitchenPantryScientist

Combine science and art to engineer and decorate a custom water bottle jacket as unique as you are. Test different every-day insulators to see what works best to to keep water cold all day long!

water bottle jacket- KitchenPantryScientist.com

You’ll need:

-a washable plastic water bottle

-flexible insulating material, like craft foam, bubble wrap or fabric batting

-decorating materials, like stickers, ribbons or foam stickies

-a thermometer (optional)

-4 disposable empty water bottles or cans that are the same size (optional)

What to do:

(Optional) Test insulators by insulating each of the empty cans or bottles with different material. Fill each of them with the same amount of hot tap water and check the temperature of each periodically to see which material does the best job of slowing cooling of the water. The one that keeps water hot the longest is the best insulator, since it slows the movement of heat from one area to another.

Use the best insulator to build an insulating case for your water bottle. Make it big enough so that your bottle will slide out for washing. We used thick craft foam and covered it with adhesive craft foam. Shipping folders made of bubble wrap work well too! Here’s how we built ours…

 

Add some ice water to the bottle and you’re good to go! Just remove the jacket when you wash the bottle.

 

CD Bots from “STEAM Lab for Kids”

 - by KitchenPantryScientist

Robots took over the driveway last summer when we were photographing my new book “STEAM Lab for Kids: 52 Creative Hands-On Projects for Exploring Science, Technology, Engineering, Art and Math”

With a few supplies from your junk drawer and a few inexpensive tech supplies available online, kids can easily make their own CD Bots! Grab a copy of “STEAM Lab for Kids” for easy instructions, or figure out how to do it yourself by attaching a toy motor (connected to a battery) to a CD with toothbrushes glued to the bottom!
Have fun!

Football Science Experiments for Super Bowl 52

 - by KitchenPantryScientist

Footballs take crazy bounces, partly due to the occasional transformation of rotational (spinning) energy to linear kinetic (forward motion) energy when  a football hits the ground. We used an experiment created by Kelly O’Shea to replicate this cool phenomenon! Try it to see for yourself how the second or third bounce can be higher than the first one! No wonder it’s so hard to catch a football!

For more Super Bowl physics fun, make paper footballs and have your own match during the big game. Here’s my ScholasticParents.com article on how to make them, how to play and the physics behind the fun! To see paper footballs in action and learn why players stay close to the ground when they tackle, check out this Super Bowl Science segment (above) I did this week on our Twin Cities CBS station.

And if you’re a Vikings fan like me…

Three Fun Science Experiments Using Bubbles

 - by KitchenPantryScientist

Blowing bubbles is a fun way to experiment with surface tension.

kitchenpantryscientist.com

Dish detergent lowers the surface tension of water which allows you to blow bubbles, and additives like glycerine, corn starch and baking soda make bubbles more elastic and resistant to popping. (More science below.)

  1. You can use a statically-charged balloon to make a bubble glide across glass as if by magic: (Instructions in video.)

2. Create a square bubble by making a cube from straws: (Submerge the cube in bubble soap made using the recipe below, pull it out, blow a bubble above it and let the bubble drop into the cube)

3. Or blow a bubble inside a bubble inside a bubble by coating a smooth surface like glass and using a straw dipped in bubble mix (recipe below) to blow bubbles inside bubbles:

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Here’s our recipe (from Outdoor Science Lab for Kids- Quarry Books 2016) that can also be used to make giant bubbles:

Mix together:

-6 cups distilled or purified water

-1/2 cup cornstarch

-1 Tbs. baking powder

-1 Tbs. glycerin (Corn syrup may be substituted for glycerine.)

-1/2 cup blue Dawn or Joy dish detergent. (Fairy, Dreft or Yes work well in Europe.)

image from “Outdoor Science Lab for Kids” Quarry Books 2016

The Science Behind the Fun (from Outdoor Science Lab for Kids-Quarry Books 2016)

Water molecules like to stick together, and scientists call this attractive, elastic tendency “surface tension.” Surfactants like detergent molecules, on the other hand, have a hydrophobic (water-hating) end and a hydrophilic (water-loving) end. This makes them very good at reducing the surface tension of water.

When you add dish detergent to water, the lower surface tension allows you to blow a bubble by creating a thin film of water molecules sandwiched between two layers of soap molecules, all surrounding a large pocket of air.

Bubbles strive to be round. The air pressure in a closed bubble is slightly higher than the air pressure outside of it and the forces of surface tension rearrange their molecular structure to have the least amount of surface area possible. Of all three dimensional shapes, a sphere has the lowest surface area. 

Of course, other forces, like your moving breath or a breeze can affect the shape of bubbles as well.

The thickness of the water/soap molecule is always changing slightly as the water layer evaporates and light waves hit the soap layers from many angles, causing them to bounce around and interfere with each other, giving the bubble a multitude of colors. Solutions like glycerine and corn syrup slow water layer evaporation, allowing bubbles to stick around longer.

Rainbow Icicles -Winter Science for Kids

 - by KitchenPantryScientist

Grab your coat and head outside to try this fun winter science project!

Rainbow Ice (kitchenpantryscientist.com)

 

You’ll need:

A large plastic zipper bag

Cotton kitchen twine

a toothpick or wooden skewer

ice-cold water

food coloring

a spray bottle

a squeeze bottle or syringe (optional, but helpful)

a very cold day (below 10 degrees F works best, but you can try it on any day when it’s below freezing)

 

Note: This experiment takes lots of playing around and results will vary depending on how cold it is outside. Remind your kids (and yourself) to be patient and try it on a colder day if it doesn’t work the first time around! If the bag leaks too quickly, try making one with smaller holes around the string.

Rainbow Ice (kitchenpantryscientist.com)

What to do:

  1. Use a toothpick or skewer to poke 3 small holes in the bottom of a zipper plastic bag. Make one in the middle and one on each end.
  2. Cut three long (3 feet or so) pieces of kitchen twine and knot them at one end.
  3. Carefully thread the twine through the holes in the bag so that the knots are inside the bag to keep the strings from falling through. Try to keep the holes from getting too big, since the bag will be filled with water and you’ll want it to drip out very slowly around the string.

Rainbow Ice (kitchenpantryscientist.com)

4. Attach two more pieces of twine to each top corner of the bag (above the zipper) to use for hanging the bag

5. Go outside and hang the bag from a low tree branch or railing.

6. Tie each of the three strings to something on the ground, like a rock, piece of wood, or the handle of an empty milk carton filled with water to weight it down. Arrange the objects so that the strings loosely radiate out at around a 45 degree angle. (See photo)

7. Add food coloring to some ice-cold water in a pitcher.

8. Fill the spray bottle with ice-cold water.

9. Add the cold colorful water to the zipper bag hanging outside. Zip the top of the back to slow the rate of leaking.

10. Immediately spray the strings with water to guide the leaking water down the strings.

10. Wait for the water on the strings to freeze. Use your syringe to add a little bit more water to the strings (same color) and wait for them to freeze again. Repeat until you have a nice layer of ice/icicles.

11. Refill the bag, using a different color of ice-cold water. Spray the strings lightly again. Repeat step 11.

12. Add layers of color to the icicles until you’re happy with the way they look!

Rainbow Ice (kitchenpantryscientist.com)

The science behind the fun:

Icicles form when dripping water starts to freeze. Scientists have discovered that the tips of icicles are the coldest part, so that water moving down icicles freezes onto the ends, forming the long spikes you’ve seen if you live in a cold climate. When you add different colors of water to icicles in sequence, the color you add last will freeze onto the tip of the ice.

Here’s a cool article on icicle science by an expert, and another great article on “Why Icicles Look the Way They Do.”

You’ll find more fun ice science experiments in my book “Outdoor Science Lab for Kids” and in my upcoming books “STEAM Lab for Kids” (Quarry Books April 2018) and “Star Wars Maker Lab” (DK- July 2018)

 

Rubber Band Car

 - by KitchenPantryScientist

It’s fun to make a rubber-band powered car from cardboard, straws, and wooden skewers!

You’ll need:

-heavy cardboard

-rubber bands

-glue (a glue gun works best)

-a plastic straw

-wooden skewers

-a CD (or a compass)

-a ruler

-screwdriverCu

-pipe cleaner (optional)

Hints: Parental supervision recommended for hot glue gun use.

Here’s what you’ll be building:

Rubber Band Car kitchenpantryscientist.com

What to do:

  1. Wrap cardboard around a large spice bottle so you can see how it bends. Cut a piece of cardboard about 9 inches (22cm) long to wrap around the bottle. Trim off the excess cardboard and tape it to create a tube.

    kitchenpantryscientist.com

  2. Trace a CD or use a compass to make 8 circles that are around 4 and 1/2 inches (12 cm) in diameter. Use a ruler to make a square around each circle and then diagonal lines to mark the center of each circle. Cut them out and glue two circles together until you have four wheels. Use skewers to poke holes through the center of each wheel.

    kitchenpantryscientist.com

  3. Poke skewers through each end of the cardboard tube, about 1 and 1/2 inches (4 cm) from the end of each tube. Make sure that the skewers are parallel and that they line up when you look through the end of the tube.

    kitchenpantryscientist.com

    kitchenpantryscientist.com

  4. Use a screwdriver to make the holes larger.

    kitchenpantryscientist.com

  5. Cut 4 pieces off of a straw that are about 1/2 inch (1.5cm) long. Glue them to the outside of each hole in the tube. Use a skewer to help align them. The skewer should spin freely.

    kitchenpantryscientist.com

  6. One at a time, put wheels on the skewers and glue the OUTSIDE of the wheel to the skewer. Make sure that the wheels are parallel to the car, and to each other as they dry. Cut off excess skewer.

    kitchenpantryscientist.com

    kitchenpantryscientist.com

  7. Poke a skewer down the center of one end of the car, parallel to the wheels so that it’s sticking out about 1 inch (3 cm.) See image above.
  8. Decorate the car!
  9. Tie three thin rubber bands together and hook them over the skewer that’s sticking out. If you have a pipe cleaner or wire, hook it onto the other end of the rubber bands. Drop the rubber bands down through the center of the tube.

    kitchenpantryscientist.com

  10. Grab the rubber bands from the end opposite where they are attached to the car. Remove the pipe cleaner hook and wind them around the skewer to create tension in the rubber bands. Wind them until they’re tight.

    kitchenpantryscientist.com

  11. Set the car down and let the wheels start to spin to see what direction the car will go. When you’re ready, let go!
  12. Measure how far the car traveled.

Enrichment: How can you make the car go faster or farther. Try using different kinds and numbers of rubber bands. How could you redesign the car to make it work better?

The Science Behind the Fun:

In this experiment, you use your body’s energy to twist rubber bands around the wooden skewer axle of a cardboard car. The energy is stored as elastic energy in the tightly-stretched rubber bands. When you let the car go, the rubber bands apply enough force on the axle to turn the wheels on the car and elastic energy is transformed into the energy of motion, which is called kinetic energy.