Discussion: You know that light, when passing from one medium to another, will refract or bend. We learned that occurs because light bends when it passes through substances, such as water and plastic. The teacher will pose probing questions to get an understanding of how much each pair grasps the idea of refraction: What do you see? The refractive index for red light in glass is slightly different than for violet light. This experiment showed that white light is actually made of all the colours of the rainbow. This is the kind of lens used for a magnifying glass.
Likewise, the room in which the experiment is being carried out could be also darker. This change of direction is caused by a change in speed. Depending on how gradual the change, you may have seen light curve! They will also receive feedback during the explain discussion portion. Step 3: Draw a large cross on the paper, in front of the mirror, but towards one side of the paper meaning not right in the middle. Since water is denser than air, when the light passed through the water it bent allowing you to see the penny at the bottom of the cup. A biconvex lens is called a converging lens. The teacher will ask the students to discuss their answers to the questions on the worksheet.
During the Elaborate portion of the lesson, the teacher will ask the students to use what they learned about light refraction to answer the question: If you are spearfishing from a riverbank and you see a fish in the water, do you need to aim above, at, or below the fish that you see in order to hit it? Does this match your prediction? If light enters any substance with a higher refractive index such as from air into glass it slows down. The teacher should elicit the prior knowledge by asking them to use what they know about light to try to explain why the pencil appears distorted. Parallel rays of light can be focused in to a focal point. For the elaborate portion of the lesson students are asked to explain how to spearfish from a riverbank. To obtain these values I used the index of refraction of crown glass because it is more likely close to the glass plexiglass that we are using. Put the angle in air on the horizontal axis. It bends toward the normal line if the light slows down in the new medium, and it bends away from the normal if it speeds up in the new medium.
Lesson Summary Reflection is where light bounces off shiny, reflective surface. There is a short quiz for the summative assessment. Since the frequency of a wave cannot change, independent of the source changing its frequency when it originally emits a wave, this change in wave velocity must result from a change in its wavelength in the second medium. But how is the angle of refraction related to the angle of incidence? When light touches the surface of the prism, refraction takes place at the boundary of the prism i. Another point to be noted here is that the angle of refraction is different for these colors as they have different wavelength. Experiment 2: Reviewing Refraction Step 1: Fill the aquarium half way with water. Introduction This laboratory was designed to investigate the behaviour of light as it travels through a less dense into a denser medium.
Based on what we saw in the experiment, this bending must be based on density, because when density changed gradually, the light bent gradually, producing a curve. They appear in the same order , just like in the rainbow. The secondary rainbow that can sometimes be seen is caused by each ray of light reflecting twice on the inside of each droplet before it leaves. Let the kids gradually move the water-filled bottle in front of the sticky note. Try to have at least 15 data points for each substance. We can see in my data that this law is true. The teacher will provide more formal written feedback when they answer the written elaborate question.
This is called the law of reflection, which says that the incident angle is equal to the reflected angle. This is due to refraction. In refraction, the characteristics of light change. These different wavelengths travel at different speeds in glass. Also we can say Sources of error could have appeared when fiddling with the pins and the lamp during the experimental procedure. Each color represents a different wavelength of light.
Explanation: Prism is made up of glass. Furthermore we are also aware of another relationship which links the angles of incidence and refraction to the refractive index of the substance used. The refractive index of violet light is 1. After answering a few questions the students are split into partners for the explore portion of the lesson. The students will be able to distinguish between reflection, refraction, and absorption, and be able to apply the information they learned about refraction to a real life situation. Since water is denser than air, when the light passed through the water it bent allowing you to see the penny at the bottom of the cup. A higher refractive index shows that light will slow down and change direction more as it enters the substance.
In this lesson plan students learn about the property of light: refraction. Use the pencil and ruler to draw the path of the light, from the laser pointer all the way to the cross. Suggested improvements to the experimental procedure include perhaps using a stronger beam of light maybe laser so as to better see the angle of refraction. Have you ever noticed that diamonds sparkle in sunlight? Continue in this manner until you have gathered data over as wide a range of angles as possible. Use an entire sheet of graph paper for each graph, and make the graph as large as is reasonable convenient.