Chapter 16.3 – Reflection and Color every object reflects some light and absorbs some light light ray – a line in space that matches the direction of the flow of radiant energy the direction of the light ray is the same as the direction light travels geometrical optics – study of light when light behaves like a ray ray diagram – diagram showing the path of light using light rays

Chapter 16.3 – Reflection and Color diffuse reflection – reflection of light in random directions by a rough surface smooth surfaces reflect light in one direction angle of incidence – angle of the light rays hitting the surface angle of reflection – angle of the light rays reflecting off the surface

Chapter 16.3 – Reflection and Color law of reflection – the angle of incidence equals the angle of reflection normal – a line perpendicular to the point where light hits a surface

Chapter 16.3 – Reflection and Color the colors we see depends on the frequencies and wavelengths of the light that reaches our eyes recall v = λ ∙ f a green object reflects green light and absorbs all other colors black objects absorb all light white objects reflect all light If we shine red light on the football field what color will it appear to be?

Chapter 16.3 – Reflection and Color additive primary colors – red, green, blue can be combined to produce all other colors is how TV and computer screens produce color subtractive primary colors – yellow, cyan, magenta - can be combined to create red, green, and blue

Chapter 16.3 – Reflection and Color Mirrors flat mirror – the image appears the same size and distance from the mirror as you are, it seems the light is coming from behind the mirror virtual image – image from which light rays appear to diverge (spread out), even though they are not focused there virtual images cannot be projected on a screen virtual images seem to be behind the mirror

Chapter 16.3 – Reflection and Color optical axis – a straight line though the center of the mirror focal point – the point where all light that travels parallel to the optical axis is reflected to meet at real image – image that is formed by the intersection of light rays - real images can be projected on a screen

Chapter 16.3 – Reflection and Color convex mirror – surface of the mirror is bulged out the image is always virtual, upright, and smaller it allows large areas to be viewed they are the side mirrors on cars

Chapter 16.3 – Reflection and Color concave mirror – the surface of the mirror is curved inwards if the object is far from the mirror, the object will be real and upside down if the object is at the focal point, there is no image, the light does not converge to form an image used in headlights and flashlights to form beams of light if an object is between the focal point and the mirror, the image will be virtual, upright, and enlarged

Chapter 16.3 – Reflection and Color