Product name: KX1937 homemade rainbow gyro
Item no: KX1937
Size: 60 * 60 * 35 mm
Weight: about 60g
Material: metal accessories + paper
Color: 7 colors
Battery use: no
Packing: 1000 PCS
Rules: 600 * 450 * 550 mm

   Gyro is an old Chinese children's toy. It is a rotating body turning on the ground. When a gyro rotates, it not only rotates around its own axis, but also makes a conical motion around a vertical axis. To make the gyro stand up, must constantly apply external force, once the loss of external help, the gyro will soon fall down, because the gyro, account for, too small to support their weight. The rotation time of the gyro is related to the distance between the pivot and the ground, the force, the contact area and the friction between the pivot and the ground.
Experimental principle:
Why doesn't a top spin? This is a dynamic unstable equilibrium. When the gyro force rotation, the total centrifugal force in all directions to reach the balance, so can temporarily stand with the shaft end. But with air resistance, ground friction, or the gyro's center of gravity, the gyro's spinning force will gradually weaken until it disappears, at which point the gyro will shake and fall.

Teaching objectives:
1. Be able to make various gyros by using the dispersion knowledge of light; In the process of playing something found, and can timely record the expression of their own research results.
2. Cultivate students' sense of cooperation in the process of making and playing a gyroscope.
3. Understand the synthesis of light and the relationship between the dispersion and synthesis of light through playing gyroscope and doing the experiment of light synthesis.

Key and difficult points in teaching:
 1. Be able to make various gyros by using the dispersion knowledge of light; In the process of playing something found, and can timely record the expression of their own research results.
2. Understand the synthesis of light and the relationship between the dispersion and synthesis of light through playing gyroscope and doing the experiment of light synthesis.

Teaching AIDS:
Material package

Board design:
A. Colours mixed Visual retention phenomenon

Synthesis of three primary colors of light

I. create the situation and perceive the problem:

Who has ever played top?
Students speak freely.
Teacher: is the top interesting?
Life: fun.
Teacher: how is it fun?
Students speak freely.
How do you play with the top?
Students speak freely.
When I was a kid, I played with a spinning top. Who has ever played with another kind of top?
Students speak freely.
Teacher: did you make it yourself? Or did you buy it?
Students speak freely.
Teacher: do you want to make one?
Living: want to.
Teacher: so let's make a top in this class today. What do we use to make a top? Very simple, a piece of paper. I believe you will do it after this lesson.

Ii. Exploring experience and solving problems:
Activity 1: make gyro.
Do you know how to make a gyro? Who would like to talk about their own assumptions.
After the students speak freely, the teacher demonstrates and explains the production methods and steps. Then let the students exchange their knowledge about the production methods of gyro. Teacher: move your little hands below to make your own gyroscope!
Make a top by hand.
During the making process, students should be reminded of the safety problem when using scissors.
T: don't forget to give the nice color on the picture of the top!
Paint the top.
Coloring requirements:
(1) ask each group to paint a top according to the proportion of the color proposed in the textbook.
(2) then let the students do in the top of the arbitrary color, can be painted two, three or more.
Activity 2: play with the top.
Teacher: the students are great. The tops are beautiful. How to make the top spin more steadily?
Answer freely.
Teacher: now let's turn them by ourselves.
   (1) repeat the experiment on each gyro painted with a different color, and carefully observe the spinning gyro's color.
   (2) instruct students to record the observed phenomenon in time so as to reciprocate the communication.
Group report communication.
Teacher summary: different colors into a color, seven colors into white.
T: if you still want to study this problem, you can look up the data in depth. This is a visual temporary retention phenomenon, (division: blackboard writing) rapid rotation
Rotation looks like a circle, so this visual persistence, can you think of any applications?
Answer freely.
Teacher: animation is the use of human visual phenomenon, so this kind of color and light mixture how to explain? I have a top here, I made it myself, what color does it spin? If you are interested, you can go back and try to make a top with rainbow color, what color does it spin? Newton once did this experiment for you, he can explain a scientific truth to you, what is it?
The student replied (by name).
Teacher: around 1666, Newton, at the age of 24, used a prism to break the white sunlight into seven colors. This is the rainbow. When he reported his discovery to the public with great joy, it was strongly opposed by the public. In order to prove that seven colors of light could be synthesized into white light, Newton conducted this experiment with a gyroscope, which made his scientific discovery understood by the public.
Activity 3: let's study the changing light
The superposition of the three primary colors of light.
1. My observation record sheet (let the students fill in by themselves first, teacher's summary)