Sunday, July 10, 2011


Science Fair Project1: Hole in the hand
You can make a hole appear on your hand by tricking your brain. Let us see how it is.
What you need?
Roll a piece of paper into pipe. Look through the tube with one eye after holding the tube with one hand next to the palm of your other hand. With the other eye look straight at your palm.
After a few seconds of observation you can see a hole in your hand. Can you see it? If you are not able to see it, try this trick with your other hand and other eye.
How it happens?
Your left eye and right eye see and send different visual information to your brain. Usually, the image information send by your both eyes will almost be the same. Therefore, your brain has no problem in combining the right and left images together. However, this trick forces your right and left eyes to see images that are so different. Then your brain blends them incorrectly. This will cause a creation of an image of a hole in your hand.
Science Fair Project2: Interference patterns
Consider two slightly separated transparent surfaces. When light hits on these surfaces, part of the light will reflect from both the surfaces. The interference will occur according to the distance between the surfaces. Constructive and destructive interference will occur, if the distance between the surfaces is a multiple of half or whole wavelengths of the light. This will produce an interference pattern.
What you need?
1. Two sheets of Plexi glass, ¼ or 1/8 inch (.64 or .33 cm) thick and approximately 1 foot (30cm) square. (size is not critical)
2. A piece of dark construction paper.
3. One 3x5 inch (8x13 cm) piece of transparent red plastic.
4. Electrical or duct tape.
5. A light source, such as desk lamp.
What to do?
1. Peel the paper from the plexi glass. If necessary, smooth all the edges using sandpaper. Be careful not to scratch the surfaces. By using alcohol and a soft cloth, you can clean the top and the bottom surfaces. To hold the plates in place, press the plates tightly together and tape around the edges. To make the interference patterns more visible, tape a sheet of dark construction paper to one plate.
2. Hold the plates with the dark paper side on the bottom, in any strong source of white light. You can see the rainbow coloured interference patterns and by bending, twisting or pressing on the plates, the patterns will change. You can also notice that the interference patterns strongly resemble the contour lines on a topographic map.
3. In between the light source and the plates, place the red plastic. Now you can notice that the patterns become red and black.
What happens?
A thin air gap will separate the light waves reflected from the surfaces of the two plastic sheets. After reflecting from the two surfaces, these light waves will meet. When these two waves meet, they can add together, cancel each other or partially cancel each other. The adding and cancelling of light waves is called constructive and destructive interference. This will create the rainbow coloured patterns that you see. 

Science experiments can be a fun way to keep kids interested in learning. These experiments explain how electricity is all around us and teach kids the basic principles of static electricity.

Charging a Fluorescent Light Bulb

Objective: This project demonstrates how our bodies contain electricity and how friction creates static electricity.

Materials Needed: A comb, a woollen scarf or sweater, a dark room, and a Fluorescent light bulb.

Experiment: Enter a dark room with the material for the experiment. Have one of the students run the comb through his hair about 20 times. Also, the comb could be rubbed back and forth on the woollen sweater or scarf to achieve the same effect. The friction from rubbing the comb through hair or on the scarf will cause electrons to travel to the comb. The friction causes the students body to become positively charged and the comb to become negatively charged. Now place the comb on the metal end of the fluorescent light bulb and watch it flicker in the dark room. As the electrons travel from the comb into the metal end of the bulb, the bulb will begin to flicker as it uses the electricity. This experiment can be used to teach the kids about positive and negative electrons and static electricity.

Using the Force

Objective: This project demonstrates how water is drawn toward electricity.
Materials Needed: A Plastic Comb, A woollen jumper or sweater, and running tap water
Experiment: Positively charge the comb by running it through a student's hair or back and forth on a jumper or woollen sweater. Once the comb has a positive charge through static electricity, turn on the tap water so that there is a small steady stream. Now take the comb and slowly move it toward the stream of tap water being careful not to let it touch the water. When the comb begins to get close to the stream of water, the students will observe that the water will begin to bend toward the positively charged comb. This experiment can be used to show the students that water conducts electricity, and that electricity is drawn toward the water. This is an excellent experiment to use to teach kids to be safe around water and electricity.

Dancing Tissue Paper

Objective: This project demonstrates the pull of static electricity.
Material Needed: Small pane of glass (about 5x10 inches), plastic zipper lock bag, two large books, small bits of paper (hole punched paper works great), foam egg carton material, metal pie pan, scissors, notebook paper

Experiment: Place the two books several inches apart on a table. Sprinkle the small bits of torn up paper between the two books and then carefully place the piece of glass on top. The pieces of paper should be visible under the glass between the two books. Begin the experiment by rubbing the plastic bag slowly back and forth across the glass. As the static electric charge begins to build between the glass and the plastic bad, the pieces of paper will begin to react. Ask the students what would happen if you rubbed the glass faster or slower. Demonstrate these changes and see if the students were able to successfully predict what would happen. This experiment can also be done by rubbing a balloon rapidly back and forth across the glass. Have the students record their observations in a science journal.

Grumpy Balloons

Objective: This experiment will show how two objects with the same electrical charge will resist each other.
Materials Needed: Two balloons, string, tape, woollen sweater or scarf, scissors, and a door frame

Experiment: Cut two equal lengths of string and hang them from the door frame. Blow up the balloons and hang them both together from the pieces of string. Make sure that the balloons are hanging evenly and slightly resting against each other. Take the balloons one at a time and rub them against the woollen sweater or scarf. Once both of the balloons are charged, gently let them hang from the strings against one another. Observe what happens when both negatively charged balloons are left to rest against each other. Because both of the balloons carry the same charge, they will resist each other and push out against the string.

No comments:

Post a Comment