Growing With Science Blog

Putting the fun back into scientific exploration

Archive for the ‘Physics’ Category

As the temperatures heat up, its time to pull out the ice and do some “cool” science.

1. Ice Spikes

Have you ever seen bumps or spikes come up from the ice cubes in your ice cube tray? SnowCrystals.com has a great discussion of ice spikes, how they form and how to grow some of your own. For more pictures and a movie, try Spikes on Ice Cubes.

2. Ice cube rescues

Give your child(ren) a challenge to “rescue” ice cubes floating in a glass of water with only a piece of string and some salt. Then watch this video to see how it is done.

3. Freezing and thawing water

Freeze water in various-sized containers and then set the ice “sculptures” out to thaw. (Set them in in deep bowl indoors or outside on a sidewalk or patio where a little melt water won’t matter.) Time how long it takes various sizes and shapes to melt with a watch or clock. Does size or shape influence melting time? How?

Try freezing a water-filled water balloon (set in a bowl first). Once it is frozen, what happens when you toss it? What happens when you freeze a balloon filled with air in a bowl of water?

4. Floating and sinking

Create an ice cube boat and float it to emphasize that ice is less dense than water.

Gather:

  • ice cube tray
  • cold water
  • pie plate or shallow bowl
  • plastic wrap
  • toothpicks
  • triangle of paper
  • clay (optional)

ice-boat
Fill the ice cube tray with water. Cover the tray with a tight layer of plastic wrap, which will hold up the toothpicks. Stick a toothpick in the center of each cube, enough so that there is a least one for each child. When the ice cubes are frozen, remove from the tray. Insert a small triangle of colored paper on each toothpick to make a sail, and float the ice cubes in a bowl of cold water (the colder the better). Do the boats float? Do they stay upright? If not, try adding some clay to the bottom until the ice cubes are balanced. (This may be difficult at first, if the oily clay doesn’t stick to the wet ice. I found it did work with patience.)

5. Moving on to dry ice

Dry ice (frozen carbon dioxide) is available at many grocery stores. Just remember that it is much colder than regular ice and will require special handling. Always use gloves, and tongs are a good idea too. Never put dry ice in a swimming pool!

See this Steve Spangler video for some ideas and handling suggestions.

Ice is so much fun to experiment with in the summer. Let me know if you have any other experiments to do with ice or activity tips.

For more information, try these books:

and these related subjects:

Ice Scientist: Careers in the Frozen Antarctic (Wild Science Careers) by Sara L. Latta

Pioneering Frozen Worlds by Sandra Markle

Beach Science- Boats

Jul-25-2009 By Roberta

To continue the theme of beach science from the last few weeks, today let’s investigate something else found at the beach.

boat

Boats!

Children are fascinated by boats and floating. You can do a lot of interesting science projects with boats, starting with some basic questions: How can huge pieces of heavy metal float? How are boats propelled? Can you really make a boat out of paper?

We already have covered some floating and boat topics in previous posts.

Why Things Float contains some experiments on floating and sinking.

The How long can a paper boat float? challenge, with the early results for paper boats challenge.
The yellow legal pad boats lasted five days.

boat

The Bathtub Buoyancy Challenge asked kids to find ways to propel boats across a bathtub without using their hands or electrical motors. The Bathtub Buoyancy results show several ways to propel toy boats.

It is always fun to build bathtub-sized boats. This video shows two handmade boats powered by battery packs and small electric motors that my son invented recently. A modified toy car powers the paddle boat; the air boat fan is a modified toy airplane propeller.

Why don’t you try inventing a boat?

For more ideas, try

A Simple Steam Boat at Curious Cat

Miniature Boats at HowStuffWorks

Hope you have fun and let us know what kind of boat you invent!

Edit: To check the rest of the posts on beach science, follow these links:

Sea Horses and Other Fish

Shore Birds

Tide Pool Invertebrates

Beach Science Algae

Beach Science-Sand

Beach Science-Seawater

Bathtub Buoyancy 3: Pumpkin Boats

Feb-13-2009 By Roberta

Continuing with the floating/boats theme we’ve had in previous posts, you just have to see this video:

What do you think? Are you ready to grow a giant pumpkin and give it a try?

Have a fun Friday!

Edit: Check this post for Why Pumpkins Float