Chapter 29- Reflection & Refraction; Physics
What is meant by the idea that a surface may be polished for some waves and rough for others?
A rough surface may regularly reflect the long waves while diffusing the shorter ones.
What becomes of a wave's energy when the wave is totally reflected at a boundary? When it is partially reflected at a boundary?
A wave's energy is totally bounced with a total reflection, while a partial reflection, the energy is bounced and absorbed.
Give an example where refraction is abrupt, and another where refraction is gradual
An abrupt change is an immediate change in medium for a light wave, but a gradual change is when a sound wave encounters a wind current, and the sound is constantly changing in speed.
Distinguish between an echo and a reverberation?
An echo is reflected sound, while reverberations are multiple reflections resulting in a jumble of waves.
Why does the blue light refract at greater angles than red light in transparent materials?
Blue reflects more than red light because the speed of the blue light changes more than red light, causing a larger change in angle.
When a wave crosses a surface at an angle from one medium into another, why does it "pivot" as it moves across the boundary into the new medium?
Each medium has its own capability to contain the wave, making the speed of the wave faster or slower.
Does the law of reflection hold for both sound waves and light waves?
If sound is reflected off of a plane surface, the law of reflection still applies.
Why do smooth metal surfaces make good mirrors?
Metal surfaces reflect almost all the frequencies of visible light.
As light passes through glass or water, do the high or low frequencies of light interact more in the process of absorption and remission and therefore lag behind?
Since the natural frequencies of glass and water are high, the high frequencies are slowed down, and are absorbed.
What is the critical angle in terms of refraction and total internal reflection
The critical angle is the angle at which a wave is only reflected and experiences total internal reflection.
When you view your image in a plane mirror, how far behind the mirror is your image compared with your distance in front of the mirror?
The distance should be the same in a plane mirror. (distance between you and the mirror and the the distance between your image and the mirror)
What is the law of reflection?
The law of reflection states the angle of incidence, or the angle which light hits the surface, is equal to the angle it is reflected upon.
Is daytime a bit long or a bit shorter because of atmospheric refraction?
The light that goes through the atmosphere is slowed down, and as a result, our day is extended 5 minutes.
What conditions are necessary for viewing a rainbow in the sky?
The sun must be shining in the sky, while the opposite part of a sky must have rain drops with clouds.
When light strikes perpendicular to the surface of a pane of glass, how much light is reflected and how much is transmitted?
when light strikes the glass perpendicularly, about 4% of its energy is reflected. Except for slight losses, the rest is transmitted.
Does the law of reflection hold for diffuse reflection?
No because the rough surface that causes diffuse reflection reflects the light into many different directions, making the law of reflection incorrect.
If light had the same speed in air and in water, would light be refracted in passing from air into water?
No because the speed is the same. This would mean that the angle does not change.
If you can see the face of a friend who is underwater, can she also see you?
No she cannot see you because the refraction of light bends the image, making it impossible to see you.
What is mean by the normal to a surface?
Normal meaning 90 degrees or perpendicular to the surface is what normal means.
Why are optical fibers often called light pipes.
Optical fibers are referred to as light pipes because they are used to transmit light from one place to another.
How is a raindrop similar to a prison?
Rain drops are like prisms because they refract light into different colors due to the water.
Distinguish between reflection and refraction
Reflection is a wave bouncing off of a surface, while a refraction is a wave going through a medium.
Does refraction tend to make objects submerged in water seem shallower or deeper than they really are?
Refraction makes objects in water appear shallower than they are. Light becomes slower in water than in air.
Is a mirage a result of refraction or reflection?
Refractions are the cause of mirages. The speed of light in hot air is faster than in slow air, and images are given by the refraction.
What is the orientation of a way in relation to the wave front of a wave?
The orientation of a ray in relation to the wave front of a wave is perpendicular.
Does the law of reflection hold for the curved mirrors?
Yes a curved mirror does follow the law of reflection.
Does refraction occurs for both sound waves and light waves?
Yes, refraction occurs for all types of waves including light and sound waves.