Light Key Terms

Reflection-the change in direction of a wave at a surface that causes it to bounce away from the surface

Angle of incidence-the angle between a ray that strikes a surface and the line perpendicular to that surface at the point of contact

Angle of reflection-the angle formed by the line perpendicular to a surface and the direction in which a reflection ray moves

Virtual image-an image formed when light rays diverge that cannot be projected on a screen

Real image-an image formed by the intersection of light rays that can be projected on a screen

Concave mirror-a mirror whose reflecting surface is the segment of the inside of a sphere

Convex mirror-a mirror whose reflecting surface is an outward-curved segment of a sphere

Refraction-the bending of a wave as the wave passes between two substances, resulting in a change of speed of the wave

Index of refraction-the ratio of the speed of light in a vacuum to the speed of light in that substance

Lens-A transparent object that refracts light rays to create images

Total internal reflection-the complete reflection that takes place within a substance when the angle of incidence of light striking the surface is greater than the critical angle

Ray diagram-diagrams used to show the path of light rays to form an image

Focal point-the point at which rays meet to form an image