Light and Mirrors: Reflection, Curved Mirrors, and Ray Diagrams

**LIGHT-** is a form of energy that is transmitted by vibrating electric charges in atoms. It travels in a straight line. It is both wave and a particle. **MAX PLANK**- light is composed of pockets of energy called *quanta (quantum).* **ISAAC NEWTON** -- light is composed of tiny particles of matt...

**LIGHT-** is a form of energy that is transmitted by vibrating electric charges in atoms. It travels in a straight line. It is both wave and a particle. **MAX PLANK**- light is composed of pockets of energy called *quanta (quantum).* **ISAAC NEWTON** -- light is composed of tiny particles of matter emitted by a source and spread outward in a straight line called *ray*. (The Particle Theory of Light) **RAY** is narrow stream of light energy, but in physics, a ray is the path taken by light energy. A beam of light is a stream of light rays. **CHRISTIAN HUYGENS** -- light consists of a series of waves with their wave fronts at right angle to the path of the rays. (The Wave Theory of Light) **PLANE MIRRORS** *Laws of Reflection:* 1. The incident ray, the reflected ray and the normal all lie in the same plane. 2. The angle of incidence and the angle of reflection are equal. *Terms used when describing the reflection of light:* - Incident ray- the ray approaching the mirror. - Reflected ray- the ray reflected by the mirror. - Point of incidence- the point where the incident ray strikes the mirror. - Normal line- the construction line drawn at right angles to the mirror at the point of incidence. - Angle of incidence- the angle between the incident ray and the normal line - Angle of reflection- the angle between the reflected ray and the normal line *Two Kinds of Image Formed in the Plane Mirror* 1\. *Virtual image*- an image formed not by the actual rays or light but by the extensions of the reflected rays. 2\. *Real image*- an image formed by the actual convergence of light rays upon a screen. **CURVED/SPHERICAL MIRRORS** *Two Kinds of **Spherical/Curved Mirror**:* 1. **Concave Mirror**- if the reflecting surface is the inner one. Also known as a converging mirror. Can also form a real and virtual image. 2. **Convex Mirror**- if the reflecting surface is the outer one. Also known as diverging mirror. Never form a real image, instead it forms virtual, erect and reduced in size and the image is located at behind the mirror. *Features of a Spherical Mirror:* 1. center of curvature- the center of a space of which the mirror is a part. 2. aperture- the diameter of a mirror. 3. Vertex-the center of the mirror. 4. Principal axis- the line drawn through the center of curvature of the vertex. 5. Secondary axis- any other drawn through the center of curvature. 6. Focus- the point between the center of curvature and the vertex. The point where the light rays meet. 7. Focal length- the distance from the vertex to the focus. It is ½ of the distance from the vertex of curvature to the focus. PARTS OF A MIRROR: a. **Concave mirror** C:\\Users\\Charlence\\Documents\\science pictures\\800px-Concave\_mirror.svg.png b. **Convex mirror**  *Image Formation by Curved Mirrors*: To create an image formed by a concave mirror, we may place a ray diagram. 1. The incident ray parallel to the principal axis is reflected through the focus. 2. The incident ray that passes through the focal point is reflected parallel to the principal axis. 3. The ray that passes through the center of curvature passes back along the same path. - The intersection of the reflected rays indicates the location of the image. C:\\Users\\Charlence\\Documents\\science pictures\\Ray Diagrams Pics.gif