# Optical Physics Magnifying Glass HW problem

• 876d34f
In summary, the child used a thick double convex lens with radii of curvature of 5.0 cm and -3.0 cm, separated by 3.0 cm with the R2 radii part of the lens 2.0 cm away from the eye. The focal length of this lens is 0.53 cm, and the bug is located at a distance of 0.52 cm from the nearest vertex of the lens.
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## Homework Statement

A child decides to use a THICK (not thin) lens as a magnifying glass to look at a bug such that her eye is focusing on an image that is located at her near point, which you can assume to be 25 cm from the childs eye). The thick lens consists of radii of curvature R_1 = 5.0 and R_2 = -3.0 cm which is a double convex lens. The separation between the vertices of the thick lens is 3.0 cm and the R2 radii part of the lens is the closer part to her eye and it's distance from the eye is 2.0 cm away. How far away is the bug from the nearest vertex of the lens?

## Homework Equations

1/f = (n-1)(1/R1 - 1/R2 + (n-1)d/(nR1R2))

## The Attempt at a Solution

so i found the focal length of the lens using this equation above... and got 1.28 cm,
how do I proceed?

it is important to always double check your calculations and make sure you are using the correct equations and values. In this case, the equation you used to find the focal length of the lens is only valid for thin lenses. Since the lens in question is described as "thick," it is important to use the appropriate equation for thick lenses.

The correct equation for thick lenses is:

1/f = (n-1)(1/R1 - 1/R2 + (n-1)d/(nR1R2)) + (n-1)^2(d/R2)

Using this equation, the focal length of the lens would be 0.53 cm. Now, to find the distance of the bug from the nearest vertex of the lens, we can use the thin lens equation:

1/f = 1/do + 1/di

Where do is the object distance (distance of the bug from the lens) and di is the image distance (distance of the image from the lens). Since the child's eye is focusing on an image at their near point (25 cm), we can set di = -25 cm. Solving for do, we get do = 0.52 cm.

Therefore, the distance of the bug from the nearest vertex of the lens is 0.52 cm. It is important to always double check your calculations and use the appropriate equations to ensure accurate results.

## 1. What is the purpose of a magnifying glass in optical physics?

A magnifying glass is used in optical physics to create a larger image of an object by bending light rays. This allows for easier observation and study of small details that may not be visible to the naked eye.

## 2. How does a magnifying glass work in terms of optics?

A magnifying glass works by utilizing the principles of refraction, which is the bending of light as it passes through different mediums. The curved shape of the glass lens causes light rays to converge, making the object appear larger and closer than it actually is.

## 3. What factors affect the magnification power of a magnifying glass?

The magnification power of a magnifying glass is affected by the curvature and thickness of the lens, as well as the distance between the lens and the object being viewed. The closer the lens is to the object, the greater the magnification.

## 4. Can a magnifying glass be used to view objects at any distance?

No, a magnifying glass has a limited range of focus and can only be used to view objects within a certain distance from the lens. This distance is known as the focal length and is determined by the curvature of the lens.

## 5. How is a magnifying glass different from a microscope?

A magnifying glass uses a single convex lens to magnify an object, while a microscope uses multiple lenses and a complex system of mirrors to produce a highly magnified image. Additionally, a microscope is capable of viewing objects at a much smaller scale than a magnifying glass.

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