W11 Activity 1 - Reflection and Refraction

W11 Activity 1 -

Law of Reflection

By Nicholas Carrillo

Decide what angles you can measure to find a pattern or relationship between the reflected and incident light-rays.

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​We are going to watch a video of laser light reflecting off a mirror.

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Poll

How do you think the incident and reflected angles compare?

• The incident angle is greater than the reflected angle.

• The incident angle is less than the reflected angle.

• The incident and reflected angles have the same value.

​What is the relationship between incident and reflected rays’ angles?

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…Let’s Find Out!

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Click this text to access activity

Use the protractor to measure Angle 1 and Angle 2

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​Move the laser pointer and measure multiple angles, what do  you notice about all the pairs of angles.

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Multiple Choice

How are the angles of the incident and reflected rays related?

• The angles have the same value

• The incident angle is less than the reflected angle

• The incident angle is greater than the reflected angle

• There is no relationship between the angles.

Law of Reflection

The angles of incident and reflected rays are the same value.

Some text here about the topic of discussion

​Now we want to look at how light bends when going from one medium to another.

​Set the incident angle to 30 degrees and measure the refracted angle

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Take the sine of both angles, and divide the incident by the refracted. 

​Now set the incident angle to 50 degrees and find the refracted angle.

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Divide the incident by the refracted angl​e. Do it again for 60 degrees.

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Multiple Choice

Which best describes the relationship you see when light goes from air to water?

• The incident angle is greater than the refracted angle

• The incident angle is less than the refracted angle

• The incident angle is the same as the refracted angle

• There is no relationship between the two.

Multiple Choice

The ratios between the sines of the incident and reflected angles should have a similar value. Which option is the closest to that value?

$$n\ =\ \frac{\sin\left(\theta_i\right)}{\sin\left(\theta_r\right)}$$  

• n = 1.43

• n = 1.37

• n = 1.29

• n = 1.33

​Refractive Index

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The index of refraction (n) determines how much light bends when going from one medium to another.

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Snell's Law

Multiple Choice

Light travels from air (n = 1.00) into a "mystery" material. The incident ray of light hits the surface at angle of 43^o and the refracted ray enters the mystery material at an angle of 27^o. What is the index of refraction of the mystery material? n₁sin(Θ₁) = n₂sin(Θ₂)

• 1.5

• 1.0

• 0.67

• 2.1

Video Response

What do you think causes the straw to appear different in the water, when compared to air?

Open Video Recorder