Detergents: Science Brings Good and Bad

We use detergents to clean many things, clothes, dishes, even cars. Dishwashing liquid is the most common detergent in the home. You might be surprised to learn that in the wrong places this great cleaner has a downside.

Materials:
Water
Large bowl
Waxed paper
Self-sealing plastic sandwich bag
Dishwashing liquid

What to Do:
Fill the bowl with water.
Crumple a large piece of waxed paper and stuff it into the sandwich bag. Seal the bag.
Float the bag on top of the water. Add several big squirts of dishwashing liquid to the water and observe. Does the bag begin to sink?

Action, Reaction, Results:
One reason that the bag floats on the surface of the water is that it has an oily coating that makes it water repellent. Detergent in the dishwashing liquid breaks up the oily coating and the bag begins to sink. Do all detergents work the same? Does it take the same amount of time for the bag to sink with different detergents?

From our experiment we can see that detergents can cause problems. Detergents in a natural water supply can cause harm to wildlife, too. For example, detergents can make water birds’ feathers less repellent to water. When hiking or camping it is important not to use detergents in or near lakes, rivers, ponds or streams.

Have a love for exploring the world around you? Sign up to help with the science fair. Contact Amy Oliver (amyroliver@gmail.com) or Anca Stepan ( ) to join the fun.

Spinning Fountain

So the sun finally came out, but the sprinkler has lost its luster and you still want water fun. What’s a kid to do? Try this on for size and see what you think.

Materials:

Empty half-gallon paper milk carton

Nail

2-foot long string

Tree branch

Directions:

1. Get an empty half-gallon paper milk carton. Use a nail to punch a hole in each left-hand corner of the carton, close to the bottom. Punch another hole in the top flap of the carton. An adult may have to help you punch the holes.



2. Tie one end of a 2-foot-long string through the hole in the top of the carton.



3. Tie the free end of the string around a tree branch so that the carton is dangling in the air.



4. Ask two friends to cover the holes in the bottom of the carton with their fingers. Use a hose or pitcher to fill the carton with water.



5. Ask your friends to remove their fingers from the carton. What happens when water squirts out of the holes?

Action, Reaction, Results:

When water squirted out the carton spun around. This happened because of Newton’s third law of motion (every action has an equal and opposite reaction). As water spurted out of the holes, it pushed back on the carton. This made the carton twirl in the opposite direction. What happens if you change the placement of the holes? Does the size of the hole matter?

More Science Fun

Looking for more fun ways to learn and do science? Check these out!

Mama Joules Science Blog http://www.mamajoules.blogspot.com/

Any of the books by Dan Green and Simon Basher:

Astronomy: Out of this World

Biology: Life as We Know It

Chemistry: Getting a Big Reaction

Periodic Table: Elements with Style

Physics: Why Matter Matters

Rocks and Minerals: A Gem of a Read

Science News for Kids Website http://www.sciencenewsforkids.org/

Facts on File Science Website http://www.fofweb.com/activelink2.asp?ItemID=WE40

Science Monster Website http://www.sciencemonster.com/

Sci Channels games website http://science.discovery.com/games/games.html or watch one of their many shows like "How It's Made" or "Morgan Freeman's Through the Wormhole".

Summer Fun: Balloon Dragsters

Who can build the fastest car? Use the directions below to build your vehicle, test it, then challenge your friends to a race. Just keep it on the track, okay?
Materials:
Piece of cardboard, 6 x 10 inches
4 straight pins
Colored markers or crayons (optional)
Flexible straw
Tape
Balloons (un-inflated)
What you Do:
Make dragster parts first. Cut 3x4 inch piece of cardboard. This will be the body of your dragster. Cut four circles, each with a 2 inch diameter, for wheels. Use a pin to poke a hole in the center of each wheel and then set the wheels aside. Decorate parts if you like.
Bend the flexible straw into an L-shape. Lay it lengthwise in the middle of the dragster’s body, with the straw’s mouth-end sticking up near the front of the car and the opposite end extending past the rear of the car. Tape the straw in place.
Put the mouth of the balloon over the mouth of the straw. Tape it in place. Just to test your tape job, blow into the open end of the straw to make sure you can inflate the balloon. If it fails, try re-taping the balloon to the straw.
Attach the wheels to the dragster body using a pin for each wheel. Test it to make sure it rolls. Make adjustments if you need to.
Blow into the straw until the balloon is half full of air. As you take your mouth off the straw, quickly block the end of the straw with your finger to keep the air in. Then let go of the straw and watch the dragster take off.
Try different sizes and shapes of balloons. Vary the amount of air in the balloons. What other modifications can you make and what effect do they have? (change the size of the wheels, or shape of body). What makes the fastest dragster?

What’s going on? Dragsters are a special kind of race car. They use the principles of rocket science to move in a straight line as fast as possible. Rocket engines and balloon dragsters work according to Newton’s Third Law of Motion. That law says that for every action (force) there is an equal and opposite reaction (force). In your dragster, the balloon pushes air through the straw—action—so the dragster moves forward—opposite reaction.

We’ll put out more fun ideas through the summer. Hey, and keep your eyes peeled for other cool stuff. We’d love to hear your ideas! You can contact Amy Oliver at AmyROliver@gmail.com.

More Sport Science!

Bazemore, Suzanne. Soccer : how it works. Mankato, Minn. : Capstone Press, c2010
Biskup, Agnieszka. Football : how it works. Mankato, Minn. : Capstone Press, c2010
Biskup, Agnieszka. Hockey : how it works. Mankato, Minn. : Capstone Press, c2010
Bonnet, Robert L. Home run! : science projects with baseball and softball. Berkeley Heights, NJ : Enslow Publishers, Inc., c2010
Dreier, David Louis. Baseball : how it works. Mankato, Minn. : Capstone Press, c2010
Gardner, Robert, 1929-. Health science projects about sports performance. Berkeley Heights, NJ : Enslow Publishers, c2002
Gardner, Robert, 1929-. Science projects about the physics of sports. Springfield, NJ : Enslow Publishers, c2000
Gardner, Robert, 1929-. Slam dunk! : science projects with basketball. Berkeley Heights, NJ : Enslow Publishers, c2010
Goff, John Eric, 1970-. Gold medal physics : the science of sports. Baltimore, Md. : Johns Hopkins University Press, 2010
Goodstein, Madeline P. Goal! : science projects with soccer. Berkeley Heights, NJ : Enslow Publishers, c2010
Goodstein, Madeline P. Wheels! : science projects with bicycles, skateboards, and skates. Berkeley Heights, NJ : Enslow Publishers, c2010
Levine, Shar, 1953-. Sports science. New York : Sterling Pub., c2006
Mercer, Bobby, 1961-. The leaping, sliding, sprinting, riding science book : 50 super sports science activities. New York : Lark Books, c2006
Rowe, Julian. Sports. Crystal Lake, Ill. : Rigby Interactive Library, 1997
Slade, Suzanne. Basketball : how it works. Mankato, Minn. : Capstone Press, c2010
Sohn, Emily. Skateboarding : how it works. Mankato, Minn. : Capstone Press, c2010
Why a curveball curves : the incredible science of sports. New York : Hearst Books, c2008
Wiese, Jim, 1948-. Sports science : 40 goal-scoring, high-flying, medal-winning experiments for kids. New York : J. Wiley, c2002

Don't Blink or You'll Miss It!

You didn’t think we were done with science did you? Think science and sports are worlds apart? Think again!
Some sports require fast reaction times: baseball, sprinting, tennis, volleyball and fencing to name a few. How fast is your reaction time? Below is a way to measure it.

Materials:
Ruler
Friend to help you

What to do:
Have your helper hold the ruler by the 12 inch (30 cm) end so that it hangs down vertically toward the ground.
Place your thumb and index finger on either side of the ruler at the 0-inch mark. Don’t squeeze the ruler—it should be able to move freely through your fingers.
Tell your friend to let go of the ruler when s/he is ready and pinch your fingers together to catch it.
Read on the ruler the distance it fell. Use the table below to determine your reaction time.

DISTANCE – REACTION TIME CONVERSION TABLE
Distance Time
2 in (~5 cm) 0.10 sec (100 ms)
4 in (~10 cm) 0.14 sec (140 ms)
6 in (~15 cm) 0.17 sec (170 ms)
8 in (~20 cm) 0.20 sec (200 ms)
10 in (~25.5 cm) 0.23 sec (230 ms)
12 in (~30.5 cm) 0.25 sec (250 ms)***

This one is all about realizing how amazing your body is. Your senses have to realize what is happening, communicate with your brain and tell your hand to grab the ruler.

Want some more science? Introduce a few variables: which of your hands is fastest, which person in your family is fastest? Try it blindfolded and have the helper make a noise as s/he drops the ruler. Collect these results. What things do you notice about your data? Keep practicing and see if you can improve your time!

***Remember milliseconds are one thousandths of a second so 1000 milliseconds (ms) = 1 second. That means 250 ms = 0.25 seconds; 100 ms = 0.100 seconds. See you’re a lot faster than you thought!

Another Great Science Fair!

Wow, 2011 held another great Science Fair for Fernwood Elementary!

Great job all of you Fernwood Students, what a wonderful group of experiments were performed, recorded and shared!

Thanks to Amy Oliver for all her hard work in making this happen!

What did you learn from your experiment? Leave a comment to share with others about what you learned.