Mirrors

This topic is claimed by Ethan Lyons

Mirrors are objects which only have one surface that is used to reflect light. This will result in the creation of images.

Types of Images

Real Images

Real images form when the rays of light converge at a focal point that actually exists. For mirrors, this means that an image is real if it is formed on the same side as the object. This means that the image is able to be projected onto another object.

Virtual Images

Virtual images form when the rays of light converge at a point that does not actually exist. For mirrors, this means that the light converges at a place behind (or through) the mirror, which is not an actual location. This means that we can see the image but it is not able to be projected. Mirrors create virtual images when the light rays converge in a spot that is on the opposite side of the object.

Basic Mirror Types

There are multiple types of mirrors which each act with light differently.

Flat Mirrors

Flat mirrors are mirrors that have flat surfaces, hence the name. We know that light will always travel in a straight line regardless of its medium. Therefore, when light comes into contact with a flat mirror, it will reflect at the same angle. This means that the angle of the incident ray will always be the same as the angle of the reflecting ray. Additionally, these will always produce virtual objects.

Convex Mirrors

A convex mirror is a mirror in which the focal point of the mirror is on the opposite side of the mirror as the object.

Concave Mirrors

A concave mirror is a mirror that has its focal point on the same side of the mirror as the object.

Optic Diagrams

Optics problems require people to draw light rays to determine where the image is formed. This allows the person to determine what type of image is formed, where it is formed, and how large it is. This can be done by finding the intersection of two of the light rays. There are three possible light rays which can be drawn, however, only 2 are required to solve each type of problem.

Types of Rays

1.The first ray you can draw starts off at the top of the real object and travels parallel to the floor until it reaches the mirror. Once it hits the mirror it reflects and travels in the direction of the focal point.

2. The second ray starts off at the top of the real object and travels directly towards the center of the mirror. The center of the mirror then acts as a flat mirror and therefore the light will will reflect off at the same angle as it arrived.

3. The third ray begins by traveling towards or through the focal point until it reaches the mirror. once it reaches the mirror it reflects back with a trajectory that is parallel to the bottom of the page.

Examples

Simple

[1]

A simple example involving a concave mirror can be found at the provided link. Notice that concave mirrors can create real or virtual images.

Middling

[2]

The link located above will take you to a video of a convex mirror problem. Take note that convex mirrors always create virtual images.

Connectedness

This topic is related because when designing and creating objects such as mirrors you have to take where it will be viewed from into account and therefore what shape of glass to use. This is particularly necessary in the designing and creating of cars and telescopes.

References

These videos were created by Leydenphysics and their Youtube channel which can be found at the below link. [3]