Problems of physical optics in the second year of junior high school, physical optics in the second

Mitsubishi mirror, the angles are all perpendicular, so each mirror can only be reflected to 2 images, the water in the basin can also be used as a mirror, so there are 6 images (you can look at the water surface as a mirror) This is a good answer, reference: we make the mirror on the left is 1, the right is 2, and the bottom is 3 First of all, the person is imaged in 1, the virtual image formed in 1, and the virtual image formed in 2 and 3 are each imaged, and there are 3 images, and then consider imaging in 2, and the virtual image in 2 is imaged again in 1 and 3 But the virtual image in 2 coincides with the image in 1 and the virtual image in 1 coincides with the image in 2, so there are already 5 images, and finally in 3, the virtual image in 1 and 2 coincides with the existing image, so it only contributes one image, so there are 6 images in total.

[The myopia lens is a concave lens, which has a divergent effect on light, and the light emitted by the candle in the second question can just converge and image on the light screen, but after being diverged by the concave lens in the third question, the angle between the light and the normal becomes larger, which is equivalent to the light source (candle) moving forward, so if you want to image, you have to move the candle back.] ]

If you don't understand, please continue to ask, and I'll be glad to answer.

If it works.

The myopia lens is a concave lens, which has a divergent effect on light, which means that if the myopia lens is not used, the image will be presented in front of the light screen, which will keep the candle away from the convex lens, which is equivalent to making the light screen close to the convex lens.

Myopic eyes can see clearly near and far because the lens has too strong refractive ability. When looking at something in the distance, the curvature of the lens cannot become small enough, as in question 3; But when the image is close to the eye, notice that the lens curvature becomes large enough to refract the image on the retina. The convex lens on the diagram cannot.

This is the reason why convex lenses cannot be considered as lenses at this time.

1, greater than. 2. Small.

3, small, same.

4. Convex lens,

2.When using the camera:

1) The distance of the object from the camera lens is greater than the distance of the film from the camera lens (greater than, less than, or equal to) - because the object distance is greater than 2x the focal length, and the image distance is between 1x and 2x the focal length.

2) The farther the object is from the lens of the camera, the smaller the image of the object on the negative; According to "things are far away like small things".

3) The image on the camera negative must be smaller than the object, and the object and the image are on both sides of the lens. -- The object is a real image of a reduced handstand at a focal length of 2x.

3.The lens of the projector is equivalent to a convex lens, and the light from the pattern passes through this lens to form a magnified inverted real image, which is reflected onto the screen after passing through the plane mirror. --The object is magnified and inverted within 2x the focal length.

4.We use a magnifying glass to look at the object and can find:

1) The image of the object being observed is magnified;

2) The object and the image formed by the magnifying glass are on the same side of the lens, and the closer the magnifying glass is to the object, the smaller the image is formed; The farther the object is from the magnifying glass, the larger the image will be. -The magnifying glass is a virtual image, which cannot be carried by a light screen, as can be seen by simple experiments.

2.(1) greater than (because the photograph is a handstand and shrinking real image) 2) smaller (the distant image of the object becomes smaller than the near image).

3) Small, both sides (ref. 1).

3.Convex lens, inverted, magnifying, real (image), flat mirror.

4.(1) Magnification (magnifying glass imaging).

2) Same (side), small, large.

2.1, greater than.

2. Small. 3) Small, both sides.

3.Convex lens, inverted, magnifying, real (image), flat mirror.

4.(1) Amplification.

2) Same (side), small, large.