Interview with Qingguang Qingguang in the shade of a tree

Hello dried bellflowers, you also like Qingguang's illustrations, we are all the same. Shake hands!

As you know, Qingguang's name on the Internet (publishing house) is Shuyin. Here's his**:

C test question analysis: light propagates in a straight line in the same uniform medium, in daily life, laser collimation, small hole imaging and shadow formation all show that light travels in a straight line in the same uniform medium Sunlight cannot continue to propagate after being blocked by leaves, and a relatively dark area is formed in the position where the sunlight is not directly irradiated, which is the shadow of a large tree, and the shade of the tree is formed due to the straight line propagation of light Compare the options, C conforms to the topic, and C is optional.

The shade of the trees is formed by the direct rays of light.

The shade of the tree is formed by the (scattering) of light.

Original question: In the hot summer, it is much cooler in the shade than in the sun, and people always like to enjoy the shade in the shade The formation of the shade is due to ( ).

a.Reflection of light bRefraction of light cStraight line propagation of light dDispersion of light.

Answer: When the sunlight is blocked by the leaves, it forms a black area underneath, forming a shade that is actually the shadow of the tree, which is formed by the propagation of light in a straight line in the same homogeneous medium. So the answer is c.

When the sunlight is blocked by the leaves, it forms a black area underneath, forming a shade that is actually the shadow of the tree, which is formed by the propagation of light in a straight line in the same homogeneous medium

Therefore, C

This is the principle of aperture imaging, no matter what the shape of the aperture is, as long as the aperture is relatively small, after the light passes through, the image formed is always the image of the luminous object. Therefore, the spot of light in the shade of the tree is the image of the sun, so it is round.

The principle of small hole imaging! It's a little gap between the leaves, and it's like the sun.

Principles of small hole imaging.

The round white dots of light are actually images of the sun on the ground through the gaps between the leaves.

Imaging of small holes and diffraction phenomena.

Using the knowledge that triangles are similar, that is, the topmost side of the great triangle is greater than the bottom side of the small triangle, which is equal to the distance between the sun and the earth than the distance from the upper hole to the ground, i.e

d::solution:d

The 9th power I hope you're satisfied, it's a simple question similar to a triangle.