Instant facts- Just add water 28

Louis Pasteur (1822- 1895) is buried in a tomb inside his own Instiute - Pasteur Institute founded in 1888 in Paris.
in http://gardenofpraise.com/ibdpast.htm

Instant facts- Just add water 27

A Praying Mantis has a average life span in the wild of 12 months
in National Geographic online

Instant facts- Just add water 26

More than 10,000 known ant species occur around the world.
in National Geographic online

Bernoulli demonstration with a ping pong ball and a hairdryer

Daniel Bernoulli was born in the Netherlands on February 8, 1700; he was a mathematician and physicist. In 1738 he published one of his most famous works: Hydrodynamica.

Bernoulli's theorem states that an increase in the speed of the fluid occurs simultaneously with a decrease in pressure. In other words the velocity increases pressure decreases.

Bernoulli's Theorem allows us to understand why planes can fly for example.

We can explain this theorem using available materials and very simple demonstrations.

What we need:

• hairdryer;
• ping pong ball;
• cardboard tube, look in kitchen for paper towels rolls.

How to:

1. Turn on the dryer;
2. Select the maximum speed and the lower temperature;
3. Point the dryer up;
4. Place the ball in the airflow, find the equilibrium, this may require some practice;
5. When the ball is stable in the air, approach the tube from the dryer.

What happens?
The ball is sucked through the tube and comes out the other side. 

Why?
Because the force balance is disturbed.


Bernoulli theorem states that a liquid or a gas lose pressure when its velocity increases. In this demonstration the ball was steady in a cold air flow, the air was moving and the pressure was low. The air exits the dryer and moves around the ball. This system is in equilibrium and the pressure is kept constant. This allows the ball to be in place.
When we add the tube to the system, we force the air to pass thru it, and therefore circulating in a confined space. This leads to the increase of air velocity, and consequently to the pressure decrease inside the tube, and that’s why the ball is sucked in the tube, in an attempt to recover the system balance.


Check out the video:

Et voilá!
Pure physics!

Enjoy!

References:
http://jonasportal.blogspot.com
Connolly, Sean, 2008 "The book of totally irresponsible science", Workman Publishing, NY

Homemade instruments- rice shaker

Sound!
All the restless children love "to do music", most of the time it's more noise than melody, but it is also true that's an important component of development.

Let's see how to build a rice shaker.

What we need:

• empty can,
• balloons, ideally busted,
• rubber bands,
• rice,
• glue,
• old newspaper and magazines,
• tape,
• pliers.

How to:

1. Wash the can, and dry it;
2. Remove the glue residues;
3. With the pliers turn inside the cutting edges of the can, this is a very simple procedure that avoids accidents later;
4. Cover the ca with the paper, fix them with the tape, apply them at will, overlap, stick them together, leave this task to your restless, they usually achieve fantastic results;
5. Let it dry, at least for 4h;
6. Place half a cup of rice inside the can;
7. Stretch the balloon with the hands;
8. Use it to close the top of the can, make sure the top of the can is closed;
9. Use the duct tape and rubber bands to help secure the balloon;
10. Repeat the procedure 2 or 3 times with different balloons, the top of the can must be tightly closed.

NOTE:

• You can paint the can after you glue the paper, use acrylic paint.
• Different seeds/ grains/ dried leguminous make different sounds, try to do several cans.

Et voilá!
Music in a can.

Enjoy!

Plastic bottle moneybox (PET)

Transform a plastic bottle into a piggy bank.

What we need:

• plastic PET bottle with cap,
• 4 PET bottle caps or 4 cork wine stoppers,
• acrylic paint,
• cardboards,
• double tape,
• exact-O knife or scissors;
• color markers;
• other materials you want to reuse, as buttons for the eyes.

How to:

1. Remove all the stickers and labels from the bottle;
2. Wash it with running water;
3. Let it dry completely;
4. Close the bottle and place it in horizontal position;
5. With the marker draw the place where you want to make the hole for the coins;
6. Use the scissors, or the exact-O knife to open the hole, this requires adult supervision;
7. Glue the 4 caps o the bottle, they must pretend they are the pig feet but most of all they must keep the bottle steady;
8. Now its time to get creative ad to make your piggy bank one of the kind, paint it and decorate it at will, reusing materials is a good option.

Tips:

• Use hot glue for the feet;
• Use double sided tape to glue the cardboard;
• If you paint the bottle paint it first with white;
• The normal acrylic paint comes off the plastic after a while.

Et Voilá!
Enjoy!

Allways the same side down- Electrical charges

This is a very simple demonstration, with an explanation beyond the obvious. This fully works using available materials. 

What we need:

• cooking oil,
• water,
• a small glass,
• cardboard,
• a charcoal,
• a puncher.

How to:

1. Fill half glass with water;
2. Fill the other half with oil;
3. Paint the cardboard with the charcoal, saturate the cardboard with the pencil as much as you can;
4. Punch little circles on the painted area;
5. Place the circles in the cup.

What happens?
The painted side always faces the oil.

Why?
Graphite is a good conductor, and has negative polarity. The polarity of the graphite repels water so that the painted face is always facing the oil.

Transform this demonstration in an experiment

1. Try other types of oil;
2. Try mixing salt or sugar in water;
3. Paint the cardboard with your colored pencils, or crayons ...

Record the observations, the falling speed of the balls and the number of times the balls fall into another position.

NOTE: You can only study one variable at a time, otherwise you will not be able to establish the cause / effect.

Et Voilá!
Electric charges at work
Enjoy!