Tuesday, May 31, 2011

Levers (hammer, ruler & thin rope)

You are given a hammer, a ruler and some thin rope. Your task is to hang the hammer from a table. The thin rope is not long enough to tie the hammer to the table.


And, up close . . . .

Momentum and Marbles


MOMENTUM

Inertia means that a rolling ball on a smooth, level surface will roll forever if nothing stops it.

In fact, friction and air pushing against the moving ball will eventually bring it to a stop.

But interesting things happen when a motionless object gets in the way of a moving one. Try this and see for yourself.



  1. Tape the yardsticks to a tabletop so they're parallel and about 1/2 inch apart.
  2. Put 2 marbles in the middle of the sticks (our 'track') a few inches apart.
  3. Flick a marble so that it rolls and hits the other one. 
Notice that the one that had been rolling stops while the one that had been still now rolls!
The momentum of the rolling marble transfers to the other one, stopping the first and setting the second in motion.
  1. Now put two marbles on the track so they touch, and a third several inches away. 
  2. Flick the single marble into the other two. 
Notice that the rolling marble stops, the middle one stays put, and the third one rolls. The momentum went through the second marble into the third.

Try other combinations: two marbles into three still marbles, or three into three. You'll find that however many marbles you set in motion, the same number will be made to roll when they're hit.

This experiment introduces 3 concepts about and momentum :
  • Momentum can transfer from one object to another.
  • Momentum can pass from one object, through a second, and into a third.
  • The total amount of momentum at the beginning will stay the same.

EXPERIMENT SUPPLIES
Supplies: Yardstick, Marble

Saturday, May 21, 2011

Oobleck (Solid or LIquid?)

See more activities in: Fifth Grade, Science
Did you know that you can change matter? Think about what happens when salt is added to an icy road on a cold winter day. It makes the snow and ice melt faster.
What happens when you get a haircut? You look different, but the hair is still made up of the same substance as before the cut- just less of it.
How about boiling an egg? Once the egg is cooked it can’t be changed back to its original condition. This is called a chemical change and it can also be seen in spoiled food, burning wood or rusted metal. Also, chemical reactions happen when something is broken apart and new matter takes its place. A great way to think of this is when a candle is lit or a cold pack melts.
Now, try to make Oobleck. What, you say? Oobleck. Do you remember the Dr. Seuss book Bartholomew and the Oobleck? This recipe will allow you and your child to create this strange substance, and witness the amazingly weird oscillation between solid and liquid that occurs!

What You Need:

  • 1 cup cornstarch
  • 1 bowl
  • 1 glass of water
  • plastic container-like an old, empty yogurt tub
  • food coloring (optional)
  • newspaper to cover the table
Note: This recipe can be very messy, but loads of fun. Wear old clothes and cover the surface you are working on.

What You Do:

  1. Put a cup of cornstarch in a bowl.
  2. Slowly stir in small amounts of water until the mixture is thick like syrup. Add a few drops of food coloring, if you choose.
  3. Squeeze the gooey mixture between your fingers. What happens? Can you shape it into a ball? Hold the ball on your flat palm. Watch what happens. What happens when you pour the mixture into another container?

Facts About Oobleck:

  • It is a solid and liquid at the same time.
  • If you make it into a ball, it looses shape when you throw it in the air.
  • It can be placed in a container, but will not take on the shape of the container when removed.
  • When you leave it in the sun, it looses its color, becomes hard on top and mushy on the bottom.
  • It does not bounce.
  • It is not edible!

Alicia Danyali, BS Elementary Education, taught primary-level students for four years at the International School of Amsterdam, The Netherlands. The last four years of her teaching career, she taught at the Washington International School in Washington, D.C. She recently completed writing a series of children's picture books and is a mother of one young son.



Source for the following info: Brain Pop Jr.

Solids, Liquids, and Gases
Background Information & Activities

Matter is all around us. It makes up all things. Scientists classify matter into three main states: solids, liquids, and gases. There are other states, like plasma, but they are mostly beyond the scope of K-3 education. Under certain conditions, matter can change between different states. We recommend watching the Changing States of Matter movie together as a review.
A solid is a kind of matter that has its own shape and does not flow at a given temperature. The molecules that make up a solid are close together and have confined movement. Solids include tables, shirts, glass cups, and clay. A property is a trait or characteristic of matter. Solids can be different colors and textures and have different degrees of malleability. It is important for young children to be able to articulate the properties of an object, as well as classify objects by their properties. Mass is the amount of matter in an object. Students may believe that mass is the same as weight, but this is incorrect. Weight is based on the gravity’s pull on an object. Thus, the weight of an object on Earth is different from weight of the same object on the moon. Mass, however, does not change and is independent of gravity.
A liquid is a kind of matter that does not have its own shape and flows at a given temperature. Liquids take the shape of their containers. The molecules that make up a liquid are farther apart than solids and are able to vibrate and move more freely. Liquids include water, blood, milk, and juice. Liquids can vary in color and viscosity, or thickness.
Like a liquid, a gas flows and does not have its own shape at a given temperature. Gases can take the shape of their containers. The molecules that make up a gas are much farther apart than solids and liquids, and can move independently. Without a container, gases can spread freely. Though you cannot always see gases, they surround us. Air is a mixture of different gases. The sun is also made up of gases. Volume is the amount of space matter takes up. Tools such as measuring cups and spoons can measure liquid volumes. The volume of a gas can be measured using specific formulas. The Sun is made of different gases and plasma. Plasma is an ionized gas, or a gas that is sensitive to magnetism.
Encourage your children to explore their surroundings and find examples of solids, liquids, and gases. How are they alike? How are they different? How do they use solids, liquids, and gases everyday?
Solids, Liquids, and Gases Teacher Activities – Click Here!
Solids, Liquids, and Gases Family Activities – Click Here!


Solids, Liquids, and Gases Teacher Activities

Shapes Matter
Remind your students that liquids take the shape of their containers. Experiment pouring liquids into containers of different shapes and sizes. Then have students pour the same amount of liquid into each container. How do the shapes change? Why do some containers appear to have more liquid than others?
As an extension, help students blow air into balloons to make different shapes. Balloons can be small, large, tube-shaped etc. Encourage students to make balloon animals to show how gas can be moved and contained. Compare how liquids and gases fill their containers.
Mass Mania
Review with your students that mass is the amount of matter in an object. Explain that some objects may seem very large but have little mass. For example, a balloon is bigger than a key, but the balloon has less mass. A foot of yarn is longer than a marble, but the marble has more mass. Brainstorm different examples. If possible, have small groups use balance scales and gram measurements to compare the masses of different objects.
Property Game
Discuss different properties of objects, such as color, texture, smell, etc. Then have students choose objects and write riddles that describe their properties. Encourage your students to write riddles for solids, liquids, and gases. Have students read their riddles and invite volunteers to guess the object. For example, a student might say: “What is solid, wooden, tall and attached to our wall?” Encourage students to think about how the objects are alike and different from each other.

Solids, Liquids, and Gases Family Activities

State House
Walk with your child around your home and find objects that are solids, liquids, and gases. Solids can include furniture and clothing, liquids can include condiments and juices in your refrigerator, and gases can include aerosol cans such as hair sprays and air fresheners. Encourage your child to describe the properties of each kind of matter and write down his or her observations in a notebook.
Liquid Lunch
Together examine the properties of different liquids in your home and compare and contrast them. You can investigate liquids such as water, heavy cream, juice, glue, rubber cement, etc. Which liquids are thick? Which are thin? Which spread quickly on a surface? Which are clear? Which liquids are harmful (toxic) and which are healthy? Which things look solid, but can be turned into liquids? Encourage your child to write his or her observations and ideas in a Venn diagram, compare-and-contrast chart, or other graphic organizer.