Principal Axis

The principal axis is an important concept in the study of optics and the behavior of light. It is a line that passes through the center of curvature (C) of a curved mirror or lens, perpendicular to the surface of the mirror or lens. The principal axis is a reference line that is used to define and measure the properties of curved mirrors and lenses.

Curved Mirrors

For concave mirrors, the principal axis is the line that passes through the center of curvature (C) and the vertex (V) of the mirror. The focal point (F) is located along the principal axis, halfway between the center of curvature and the vertex. The focal length of the mirror is the distance from the focal point to the vertex along the principal axis.

For convex mirrors, the principal axis is the line that passes through the center of curvature (C) and the vertex (V) of the mirror. The focal point (F) is located behind the mirror along the extension of the principal axis. The focal length of the mirror is the distance from the focal point to the vertex along the principal axis.

Curved Lenses

For converging lenses (convex on both sides), the principal axis is the line that passes through the center of curvature (C) of both surfaces of the lens. The focal point (F) is located along the principal axis, halfway between the center of curvature and the lens. The focal length of the lens is the distance from the focal point to the lens along the principal axis.

For diverging lenses (concave on both sides), the principal axis is the line that passes through the center of curvature (C) of both surfaces of the lens. The focal point (F) is located behind the lens along the extension of the principal axis. The focal length of the lens is the distance from the focal point to the lens along the principal axis.

Study Guide

What is the principal axis?
How is the principal axis related to concave and convex mirrors?
How is the principal axis related to converging and diverging lenses?
What is the focal length and how is it related to the principal axis?

Understanding the principal axis is crucial for comprehending the behavior of light in curved mirrors and lenses. Mastering this concept will enable you to analyze and predict the formation of images and the properties of optical systems.

◂Science Worksheets and Study Guides Eighth Grade. Volcanoes

Vocabulary/Answer key

Volcanoes

Vocabulary/Answer key

Volcanoes

Vocabulary/Answer key

Volcanoes

The resources above cover the following skills:

Earth/Space Science: Students will use scientific skills and processes to explain the chemical and physical interactions (i.e., natural forces and cycles, transfer of energy) of the environment, Earth, and the universe that occur over time.

Earth History: Explain how sedimentary rock is formed periodically, embedding plant and animal remains and leaving a record of the sequence in which the plants and animals appeared and disappeared.

Explain how sedimentary rock buried deep enough may be reformed by pressure and heat and these reformed rock layers may be forced up again to become land surface and even mountains.