Tuesday, June 29, 2010

IMMOBILE

PURPOSE : To determine if each finger can move independently.
MATERIALS : Your hands
PROCEDURE :
  • Place the tips of your ring finger together.
  • Fold the other fingers down so that the second set of knuckles touch
  • Try moving the ring fingers apart by moving them backwards. You may not slide the fingers sideways and the knuckles must remain together.
  • Experiment to test the independence of the other fingers. Place all the knuckles together except the two fingers to be tested.

RESULTS : You will be unable to separate the ring fingers and the center fingers. The index and the little fingers are easily moved.
WHY? A ligament connects the ring finger to the middle finger and other digits. Immobilizing either the middle or ring finger prevents the movement of the other finger. The index and little fingers seems to work independently of the other fingers.

HEARING

PURPOSE : To demonstrate how sound is heard.

MATERIALS :
                               Metal spoon
                               2 feet (61 cm) of kite string
                               Ruler
PROCEDURE :
  • Tie the handle of the spoon in the center of the string.
  • Wrap the ends of the string around both index fingers. Be sure that both strings are the same length.
  • Place the tip of an index finger in each ear.
  • Lean over so that side of a table.
RESULTS : It sounds like a church bell.


WHY ? The metal in the spoon start to vibrate when struck. These vibrations are transmitted up the string to the ears. The ability to hear is due to one’s ability to detect vibration. Objects must vibrate to produce a sound. The vibrating object causes the air around it to move. Vibrating air molecules enter the air and strike the air drum causing it to vibrate. These vibrations continue to travel through bones and fluids in the ear until they reach a nerve that sends the message to the brain.





EYE LENCE

PURPOSE : To demonstrate how an eye lens works.

MATERIALS : Magnifying glass

                        Sheet of typing paper

                        Ruler
PROCEDURE :
  • Darken a room.
  • Hold the magnifying lens about 5 feet from an open window.
  • Position the paper on the opposite side of the lens from the window.
  • Slowly moves the paper back and forth from the lens until a clear image of the window and object outside appear.
RESULTS : A small colored inverted image forms on the paper.
WHY ? Just like the lens in a human eye, the light changes direction as it passes through. The light hits the paper as light hits the retina when it passes through the lens of an eye and forms an inverted image.



Saturday, June 26, 2010

SPICY ESCAPE

PURPOSE : To demonstrate diffusion and osmosis .

MATERIALS : Eye dropper
                          Vanilla extract
                          Balloon ( use small size )
                          Shoebox

PROCEDURE

  •  Place 15 drops of vanilla extract inside the deflated balloon. Be careful not to get any of the vanilla on the out side of the balloon.
  •  Inflate the balloon to a size that will comfortable fit inside the shoebox and tie the open end .
  • Place the balloon in the empty shoebox . Leave the balloon in the closed box for one hour .
  •  Open the box and smell the air inside .

RESULTS : The air smells like vanilla . The box is still dry .

WHY ? The balloon appear to be solid , but it actually has very small invisible holes all over its surface .The liquid vanilla molecules are too large to pass through the holes , but the molecules of vanilla vapor are smaller than the holes and pass through . The movement of the vapor through the rubber membrane is called osmosis .


The escaped vanilla vapor move through the air in the shoebox . And once the shoebox is open , through the air in the room . This spontaneous movement of molecule from one place to another is called diffusion . If u wait long enough , the diffusion will result in a uniform mixture of the vanilla vapors and the air with which it mixes .

HUNGRY FUNGUS

PURPOSE : To observe the effect that yeast has on a sugar solution.

MATERIALS : 1Package of powdered yeast
                           Sugar
                           Glass soda bottle
                           Measuring spoon – tablespoon (15 ml)
                           Measuring cup (250 ml)
                           10 inch (25 cm) balloon

PROCEDURE :

  •  Mix the package of yeast and one spoon of sugar in one cup of warm water. Be sure the water is warm, not hot.
  •  Pour the solution into the soda bottle.
  •  Add another cup of warm water to the soda bottle.
  •  Squeeze the air out of the balloon and place it over the mouth of the bottle.
  •  Observe the bottle daily.

RESULTS : Bubbles are continuously being formed in the liquid. The balloon is partially inflated.

WHY ? Yeast is a fungus. It has no chlorophyll like other plants and cannot produce its own food. Like animals, yeast can use food such as sugar to produce energy. The yeast causes the sugar to change into alcohol, carbon dioxide gas, and energy. The bubbles observed in this experiment are carbon dioxide. This same gas causes bread to rise during backing as the bubbles push the moist dough up and out ward. Gas holes can be seen in the finished bread. The nice smell from the backing of yeast bread is partially due to the evaporation of the alcohol produced.

WATER BREATH

PURPOSE : To explain how camels can live in the desert for weeks without drinking water.

MATERIALS : Hand mirror

PROCEDURE :

  • Breathe onto the mirror.
RESULTS : The mirror becomes fogged with tiny droplets of water.

WHY ? Exhaled breath of humans as well as camel contains water vapor. Some of the water in breath goes into the air and some remains in the passage inside the nose. The passage inside the human nose is short and relatively straight. The camel’s nose has long twisting passage. Most of the water in a camel’s breath stays inside the nose instead of escaping into the air. This allows camels to go longer without drinking because they do not lose as much water through their exhaled breath.

HIDDEN PICTURE

PURPOSE : To observe the camouflaging technique of animals.

MATERIALS : Red transparent plastic folder
                           Pale yellow crayon
                           White typing paper

PROCEDURE :

  • Draw a bird on the white paper with the yellow crayon.
  • Cover the drawing with the red folder.
RESULTS : The yellow bird disappear.

WHY ? The yellow bird and red folder both are reflecting light to your eyes. The red is not a pure color, but has some yellow in it. This yellow blend in with the yellow from the bird drawing, and your eye is not sensitive enough to separate them. Animals that have similar colorations as their environment are often camouflaged, hidden from prey. The stalking animal’s eyes cannot distinguish the colors enough to separate its meal from the leaves.

GROWTH RATE

PURPOSE : To measure the growth rate of a plant stem grown in the shade

MATERIALS : 2 Green onion
                          Glass
                          Soil
                          Ruler
                          Marking pen (black)

PROCEDURE :

  •  Measure about 6 inches (15 cm) from the root of each onion and have an adult cut off the stem.
  •  Fill the glass with soil.
  • Moisten the soil with water.
  •  Stick the closed end of the marking pen into the soil near the glass and move it back and forth to make a hole. The hole needs to be large enough to bury the onion root 2 inches (5 cm) below the soil surface.
  •  Insert the onion, root down, into the hole.
  •  Push the soil around the onion to secure it in place.
  •  Do this for both the onions. Place the glass away from a window.
  •  Use the marking pen to color around the end of each onion stem.
  • Use the pen to mark the stem each day. The new growth will grow out of the outer skin covering.
  • Observe and mark the stem daily for 2 weeks.

RESULTS : The stems may grow at different rates, but they can grow as much as 12 inches (30 cm) in 2 weeks .

WHY ? Plants need water, nutrients, and sun light to grow properly. Their growth changes when any one of these three factors is lacking. The lack of sufficient sunlight causes a plant to grow very tall. Many bedding plants have very long stems because they do not receive enough sunlight. Trees in a thick forest are often thin and very tall so that they can reach upward to the sun. Your onion plant has grown very tall because of the lack of sunlight.