Light Through Materials
Light passes through this type of material clearly, allowing you to see objects on the other side.Light passes through this type of material clearly, allowing you to see objects on the other side.
What is transparent?
You look into a mirror and see your face because light bounces off the mirror.
What is reflection?
Light hits a smooth mirror and bounces back. What happened to the light?
It was reflected.
Under white light, a blue shirt looks blue. Which color of light is mainly reflected to your eyes?
Blue light
A light becomes brighter. What happens to the amplitude of its light wave?
The amplitude increases.
Cardboard blocks light from passing through. Cardboard is this type of material.
What is opaque?
A black shirt gets warm in sunlight because it takes in much of the light energy.
What is absorption?
Light strikes a dark surface and does not bounce back or pass through. What happened to much of the light?
It was absorbed.
A red apple appears red under white light. What happens to the red light, and what happens to much of the other visible light?
Red is reflected; much of the other light is absorbed.
A light becomes dimmer. What happens to its amplitude?
The amplitude decreases.
Light passes through wax paper, but it scatters, making objects behind it look blurry.
What is translucent?
A straw appears bent when placed in a glass of water because light changes direction as it enters a different material.
What is refraction?
Light travels from air into water, changes speed, and bends. What happened?
It is refracted.
Why does a black object appear black under white light?
It absorbs most visible wavelengths and reflects very little light to our eyes.
A red light shines on a red object. Predict how the object will appear and explain why.
It appears red because the object reflects the available red light.
A beam of light travels through a clear glass window. Name the main interaction occurring.
What is transmission?
Light hits a rough wall and reflects in many different directions instead of producing a clear image.
What is diffuse reflection?
White light enters a prism and bends. The different wavelengths bend by different amounts. What happens to the white light?
It refracts and separates into the colors of the visible spectrum.
Why does a white object appear white under white light?
It reflects most/all visible wavelengths of light.
A green light shines on a blue object in a dark room. Predict what you will see and explain why.
The object appears very dark because it normally reflects blue light, but blue light is not available; much of the green light is absorbed.
Compare transparent and translucent materials. Light can pass through both, but why can you see clearly through only one?
Transparent materials transmit light with little scattering; translucent materials scatter the transmitted light.
A flashlight shines through wax paper. Some light passes through, but it spreads in many directions. Name TWO interactions occurring.
What is transmission and scattering?
A beam enters a clear glass block at an angle, bends as it enters, travels through the glass, and exits the other side. Identify TWO light interactions involved.
Refraction and transmission
Blue light shines on a red object in a dark room. Why will the red object appear very dark or nearly black?
The red object normally reflects red light, but no red light is available. Much of the blue light is absorbed, so very little light reaches our eyes.
A student says, “An object has its own color, so a red object will always look red no matter what color light shines on it.” Is the student correct? Explain using reflection and absorption.
No. The color we see depends on the wavelengths available and which wavelengths the object reflects and absorbs. If red light is not available to reflect, a red object may appear very dark.