Here s a simple physics question

This is a matter of perspective, the same person, when you are close to you, you look at him tall, and when you are far away from you, you look at him short, isn't it? In addition, no matter how tall the building is, if it is far away from you, it may not be as tall as the people around you, why? The perspective is different!

The objective lens of the Galilean telescope creates a reduced image between one and two focal lengths, and the purpose of the eyepiece is to magnify this real image! So in fact, the role of the objective lens is to shorten the distance of the image!

The stars we see are already too big, is it necessary to zoom in again?

The image seen through the telescope is inverted and shrunk, but the image is very close to our eyes, just like a person in the distance to see in front of us, it must be clear! Enlarged viewing angle.

Don't think of the problem as simplistic, there are many principles that you don't know. You'll understand later, and I'll tell you you don't understand either.

First of all, let's talk about the inverted image. In fact, Galileo's telescope is an inverted image. It's just that he didn't know it at first.

It was his mother, who looked at the moon with his telescope and said to him, "My dear son, why does the moon I see through the telescope seem to be upside down from the moon I usually see?" Then Galileo learned that his telescope was inverted.

Our teacher said. The teacher also said that this story reflects that behind a great person, there must be a great mother.

Let's talk about shrinking. It's like if you look at an object 100 meters away, 100 meters high, or an object 10 meters away, which is better? The latter, of course, is narrower, but it opens wider to your eyes, so you can better distinguish the details on it.

This is the principle of expanding the perspective.

The eyepiece of the Galilean telescope is placed within one time of the focal length of the objective lens, and before the object has time to converge to the image point, it falls on the concave lens, which cancels out the convex lens convergence of the human eye, so that objects much larger than twice the focal length will be imaged directly to the retina. It's upside down, but it looks like it's tidy to the human eye.

If it's not a matter of lens proportions, then you have to think differently! Galileo used a telescope 1.2 meters long, did he put two lenses 1.2 meters away?

It's okay to find a way to pour it again.

The Galilean telescope has a bend in the back.

So when you look down, you don't change the direction of the Galilean telescope.

Then there is a mirror at the bend.

No, telescopes have two lenses.

Both the objective lens and the eyepiece should have concave lenses.

1. The water vapor in the air increases when the tide returns, and the hot water vapor meets the cold tiles and glass, and the liquefaction phenomenon attaches to the tiles and glass, which is similar to the sweating of tiles and glass.2 When the indoor temperature exceeds 40 degrees Celsius, the polyethylene material in the cement of the Dongjing section will liquefy the draft and absorb heat vertically to inhibit the rise of indoor temperature, and when the indoor temperature is lower than 15 degrees Celsius, the polyethylene material in the cement will solidify and release heat to inhibit the indoor air temperature from decreasing.

1. Press s=

Let the first paragraph t1=t; displacement s1=;

The total time from rest to the passage of the second segment t2=3t; Total displacement s2=;

The total time from rest to the third passage time t3=6t; Total displacement s3=;

The ratio of the three displacements is:

Displacement S3 - Total displacement S2: Total displacement S2 - Displacement S1 : Displacement S1 = 36 - 9:9 - 1:1 = 27:8:1

The area method can also be used.

2. Three-force equilibrium, that is, the resultant force of any two forces is equal to the third force and opposite in direction.

F2 is perpendicular to F3, which means that F2*F2+F3*F3=F1*F1 can be generated if F1 is removed.

Illustrates that f1 alone can be generated; f1=

Remove the acceleration that f2 can produce.

Illustrates that f2 alone can be generated; f2=

f2*f2+f3*f3=f1*f1

f3 = 2m and removing f2 can produce an acceleration of 2m s 2.

1) Solution: Displacement ratio with zero initial velocity First second: Second Second: Third second: .nth second = 1:3:5:.2n-1

2) Solution: Let the acceleration after removing fn be an, and the mass of the object is mf1=a1m=after removing f1, the net force on the object is f1, and the direction is opposite to f1. f2, f3).

f2=a2m=

f3=a3m

f1^2=f2^2+f3^2

f3^2=(

f3=2m=a3m

a3=2 (m/s^2)