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Opaque objects block light and form shadows.. Presentation..[r]
(1)Light
Unit Lesson 2: (Duration 35 mins)
(2)Revision
(3)Warm up
Fill in the blanks
1 The Sun and torches are l _ _ _ _ s_ _ _ _ _ _
2 A light source can p _ _ _ _ _ _ light.
(4)(5)How light travels?
Experiment:
1 Preparation:
- laser led
- Some pieces of paper with a hole in the middle
2 Result:
(6)Light travels in straight line.
Light cannot travel in bended path.
(7)When light cannot go past an object, it forms a shadow.
(8)Opaque objects block light and form shadows.
(9)Unit 6-Lesson 2: How does light travel? Travel: di chuyển
2 Straight line: đường thẳng Opaque: vật chắn sáng
4 Bended line: đường cong Shadow: bóng
(10)(11)(12)Let’s make some shadows of animals
(13)Light travels in straight line.
Summary