The total number of segments is 14, and the number of audio-visual segments is 14.
First, the teaching objectives
Scientific concept
1, the sun is the largest light source and heat source on the earth.
2. The color of an object is related to its heat absorption capacity. Dark objects absorb more heat than light objects.
3. The relationship between the angle of sunlight exposure and heat absorption. Objects absorb the heat of sunlight vertically faster than obliquely.
Process and method
1, do experiments to explore the relationship between object color and heat absorption ability.
2. Do experiments to explore the relationship between heat absorption of objects and direct and oblique sunlight.
3. Draw the experimental data of object color and temperature rise into a line chart.
Emotions, attitudes and values
1, can operate in strict accordance with the experimental requirements in the experiment, and record and observe the experiment realistically.
2. Recognize that changes in natural things are related.
Agree that the development of science and technology can make people make better use of natural resources and natural laws.
Second, teaching preparation.
Teacher demonstration: courseware and pictures of human using solar energy
Group experiment: paper tape and thermometer made of white paper, art paper, black paper, black wax paper and aluminum foil paper folded in half; Three identical black paper strips are inserted with thermometers respectively.
Third, the importance and difficulty of teaching
Comparative experiment: the relationship between object color and heat absorption; Relationship between heat absorption of objects and direct and oblique sunlight
Fourth, the class schedule
1 class hour
Teaching process of verbs (abbreviation of verb)
1, importing
1) The sun is the largest light source and heat source on the earth; Humans only use a small part of solar energy, and most of the light and heat are not fully utilized. Besides concentrating sunlight with concave mirror and convex lens, what else can we do to get more light and heat from the sun?
2) Students can express their opinions freely.
2, the color of the object and heat absorption.
1) Is the color of an object related to heat absorption? Ask students to learn the requirements in the book by themselves.
1) Teachers and students discuss the matters needing attention in this comparative experiment.
Except for the different colors and smoothness of the paper, other conditions, such as the place, method and time of placement, should be kept consistent as far as possible.
3) Students' experiments and records
3. The relationship between the heat absorption of an object and direct or oblique sunlight.
1) student reading experiment scheme
1) Points for attention in students' analysis and comparison experiments
2) Students' experimental records
4. Draw the observed data into a chart.
1) The teacher explained the painting method.
What do the horizontal and vertical axes mean?
What is the scale value?
The colors of dots and lines should be drawn according to the requirements of textbooks.
2) Analysis
Why does black wax paper heat up more slowly than black matte paper?
The heat absorption capacity of aluminum foil paper is relatively small.
1, summary
Review Lesson 5 and Lesson 6 and sum up what we can do to get more light and heat from the sun.
Six, homework design
Understand the design, structure and working principle of solar water heaters and solar cookers.
Seven, blackboard design
2.6 How to get more light and heat
Comparative experiment 1: color and heat absorption of objects
Comparative experiment 2: the relationship between sunlight irradiation angle and heat absorption
line chart