Bellringer Give the number and unit for the speed at which all Electromagnetic waves travel in both long form and scientific notation.

Light Part I

When Light Strikes an Object When light strikes an object, the light can be reflected, transmitted (pass through), or absorbed (no reflected or transmitted light). Materials can be transparent, translucent, or opaque. It depends on what happens to the light that hits the materials.

When Light Strikes an Object Transparent materials let most light pass right through. You can see clearly through a transparent material. Clear glass is a transparent material.

When Light Strikes an Object Translucent materials scatter light as it passes through. You can see things through a translucent material, but the details are blurred. Wax paper is a translucent material.

When Light Strikes an Object Opaque materials do not let light pass through. They reflect or absorb all the light that hits them. When materials absorb light, they take in light. You cannot see anything through an opaque material. Wood is an opaque material.

The Color of Objects The color of an opaque object is the color of the light it reflects. The color of a transparent object or translucent object is the color of light it transmits. The color of any object depends on what the object is made of and the color of light that hits it.

The Color of Objects Objects made of opaque materials reflect some light and absorb the rest. The color of the reflected light gives an opaque object object its color. For example, an apple looks red because it reflects red light and absorbs light of other colors.

The Color of Objects Objects made of transparent or translucent materials transmit, or let through, light of only certain colors. The color of light that passes through a transparent or translucent object gives the object its color. For example, in sunglasses only let green light pass through, the glasses look green.

Combining Colors When combined in equal amounts, the three primary colors of light produce white light. As pigments are added together, fewer colors of light are reflected and more are absorbed, leading to a darker pigment. Primary colors are three colors that can mix together to make any other color. Two primary colors mix in equal amounts to make a secondary color.

Combining Colors Primary colors of light are red, green, and blue. Secondary colors of light are yellow (red and green), cyan (blue and green), and magenta (blue and red). Equal amounts of all three primary colors of light mix together to make white light.

Combining Colors Pigments are colored materials. They are used to color inks and paints. Pigments have different primary and secondary colors. Primary colors of pigments are yellow, cyan, and magenta. Secondary colors of pigments are red (yellow and magenta), green (yellow and cyan), and blue (cyan and magenta). When equal amounts of all three primary colors are mixed together, the mixture looks black.

Reflection of Light Rays The two ways in which a surface can reflect light are regular reflection and diffuse reflection. You can think of light waves as straight lines called rays. Light rays can reflect, or bounce off, mirrors and other shiny surfaces.

Reflection of Light Rays When light rays bounce off of a smooth surface, it is called regular reflection. All light rays are reflected at the same angle . The reflection is sharp. When light rays bounce off of a bumpy surface, it is called diffuse reflection. The light rays are reflected back at various angles. This reflection is blurred.

Plane Mirrors A plane mirror produces a virtual image that is upright and the same size as the object. A plane mirror is a flat sheet of glass that has a smooth, dark coating (usually made of silver) on the back. The coating reflects all the light that hits it. Most bathroom mirrors are plane mirrors. What you see when you look in a mirror is an image. An image is a copy of an object.

Plane Mirrors The image you see in a plane mirror is called a virtual image. A virtual image is an image that forms where the light seems to come from. The image looks as though it is behind the mirror. A virtual image is always upright, or right side up. But the image is not quite the same as the object. the left and right of the image are reversed.

Virtual