```Reflection, Refraction, and Diffraction Mini-Labs
Tennis Ball Angles (Reflection Lab)
1. Sit on the floor and roll a tennis ball toward the wall directly in front of you. What happens to the ball?
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2. Mark this line as the normal line. It should be perpendicular to the wall.
3. Now roll the ball at increasing angles to the normal line. Measure the angle you will release the ball from the normal line (Angle
of Incidence) and measure the angle the ball bounces off the wall (Angle of Reflection).
Record this in your data table. Repeat four more times. (See page 407, figure 12-20 in your book to guide you.)
Bounce Number
Angle of Incidence (the angle the
ball approaches)
Angle of Reflection (the angle the
ball bounces back)
4. What do you notice about the angle of incidence and the angle of reflection?
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5. How would the information you learned from this lab, improve a person’s pool game?
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Pencil in a Glass (Refraction Lab)
1. Place a pencil in a clear glass of water.
2. Observe the pencil from the front of the glass. (Bend down so the glass is at eye level).
3. What do you notice about the pencil?
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4. Draw a picture of the pencil and the glass. Draw the normal line and label the angle of refraction.
Bubbles (Reflection/Refraction Lab)
1. Blow a bubble by using a straw or cup with a hole cut in the bottom.
2. Sit your bubble on the top of the pie pan and observe. Draw your observations below. Be detailed.
Bubbles floating
Bubbles on pan
Bubbles with an object (like your hand
inside)
1. Why do bubbles appear rainbow like in color?
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2. Why can I see my reflection in a bubble?
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3. Explain how it’s possible to poke objects in a bubble and why it is possible.
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Diffraction investigation
1. Go to http://www.acoustics.salford.ac.uk/feschools/waves/diffract.htm
2. Using the animations on-line investigate how waves are diffracted.
3. Be sure to include detailed drawings and labels.
4. Complete the online questions.
Light Wave – How do light waves behave around corners? (Draw what you observe.)
1. Describe how a light wave behaves around a corner. How does size affect the wave?
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Diffraction investigation Cont.
Sound Wave – How do sound waves behave around corners? (Draw what you observe.)
2. Describe how a sound wave behaves around a corner.
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Barriers– How do waves behave when they encounter a barrier in a ripple tank? (Draw what you observe.)
Large Object
Medium Object
Small Object
3. Describe how waves behave in a ripple tank when they encounter a barrier.
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Slit/Gap Size – Describe how the size of a gap affects the type of wave produced. (You will need to go to page 3 of this site by
hitting the next button at the bottom of the page.)
One Slit
Two Slits
4. Describe how waves behave when they pass through a slit or gap.
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5. When would knowing about a barrier and how a wave behaves be helpful? (Hint: Read page 2 of the online lab you are at.) Be
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