Classwork/Homework
Name: __________________________
4th grade PSI
-----------------------------------------------What are Waves?
Classwork
1. True or False: Waves are not regular patterns of motion that
are caused by a disturbance.
2. How can you produce waves in a basin of water?
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3. A _______________ wave moving along a rope will cause
each piece of rope to move up and down.
Homework
4. How do you make a transverse wave move through a rope?
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________________________________________________
5. Explain the direction that a transverse wave moves through
water and the motion of the drops of water.
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________________________________________________
________________________________________________
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6. If the surface of water is calm and no disturbance is moving
across the surface, this is referred to as ________________.
-----------------------------------------------Describing Waves
Classwork
7. In the following picture, label all the parts of the wave:
Homework
8. What is the highest point a wave will reach called?
_____________________
9. What is the lowest point a wave will reach called?
_____________________
10. The distance from the dotted line running through the
middle of the wave to either the crest or trough is called the
_____________________.
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11. The distance between two close crests of a wave is called
the _____________________.
12. What makes a wave periodic?
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_______________________________________________
-----------------------------------------------Sound
Classwork
13. The _____________________ around you is occupied by
very small objects that we call particles. You can’t see them
because they’re too small.
14. A _____________________ moves through the air through
a series of collisions.
15. Compare and contrast the motion of particles in a
transverse wave and a longitudinal wave.
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_______________________________________________
_______________________________________________
_______________________________________________
_______________________________________________
16. True or False: Sound is an example of a transverse wave.
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Homework
17. True or False: Higher pitched sounds are always louder
then lower pitched sounds.
18. Can sound move in outer space? Support your argument
with some facts you know about space and longitudinal
waves.
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_______________________________________________
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-----------------------------------------------Sight
Classwork
19. We need _____________________ in order to see.
20. So far, we learned that three things could happen to light, it
can either be absorbed, bent, or _____________________.
21. The sun and other light sources give off
_____________________ of light. They will continue on in
straight paths until they collide with something else.
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Homework
22. Why can’t we see in the dark?
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_______________________________________________
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23. True or False: We can see an object because after the light
hits the object it is reflected back to our eyes.
-----------------------------------------------Color
Classwork
24. What colors do you get after passing a beam of white light
through a prism?
_______________________________________________
25. True or False: All of the colors are contained within a beam
of white light.
26. True or False: The color we see is the color that is
absorbed by the object.
Homework
27. The color that we see is _____________________ off the
object; this is why we see that color instead of all the other
colors.
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28. A box appears red because it _____________________
the color red and _____________________ the rest of the
other colors.
29. If nothing is reflected off the surface of the object what color
do you see?
_______________________________________________
_______________________________________________
-----------------------------------------------Mirrors
Classwork
30. True or False: Light reflected off the surface of a mirror will
go off at a different angle then the one it hit the mirror.
31. If an object is located 5 meters in front of a plane mirror,
how far will the image appear behind the mirror?
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Homework
32. Which path will the beam of light take after hitting the mirror
or mirrors? (The colors for the paths are just meant to make
it easier to see the different paths of light, we are not asking
anything about color here!)
-----------------------------------------------Refraction
Classwork
33. Describe what you see when you place an object like a
ruler or pencil into a glass of water.
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_______________________________________________
Homework
34. Why does the ruler or object placed in the water appear to
be bent?
_______________________________________________
_______________________________________________
_______________________________________________
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35. What do we call the bending of light when it happens from
moving from one material into another?
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_______________________________________________
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-----------------------------------------------Digitized Information
Classwork
36. Information is transmitted through waves, how does a
cellphone convert from one wave to another to transmit
what you are saying to someone else?
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_______________________________________________
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37. If you needed to communicate with someone right next to
you and didn’t have to be quiet, what would be the easiest
way?
_______________________________________________
38. If your friend was away on vacation in Europe, what would
be the easiest means of communication?
_______________________________________________
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Homework
39. Binary code is comprised of 0’s and 1’s to communicate
information. If we wanted to form the image of an x on a
3x3 grid what would be the string of numbers we would
need to input (remember, go left to right on the top row,
then left to right on the middle row, then left to right on the
bottom row)?
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____________________
40. If you are given a 3x3 grid and the string of numbers:
100010100 and told that the number 1 represents a black
square and the number 0 represents a white square, what
image would you have made?
answer: ____________________
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41. Write the following message in Morse Code: Hello World
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Waves & Light Classwork/Homework Answer Key
4th grade PSI
---------------------------------------------------------------What are Waves?
Classwork
1. False: Waves are regular patterns of motion that are caused by a disturbance.
2. Hitting the water with an object or dropping something into the water will cause
waves to move outwards from that point.
3. Transverse
Homework
4. Fix the rope at one end and move the other end up and down to make the
transverse wave.
5. In a water wave the transverse wave is moving away from the point where the
rock was dropped into the basin or where the water was struck. As it moves
away it causes the water drops to move up and down.
6. If the surface of the water is calm, no disturbance is moving across the surface,
this is referred to as Equilibrium.
Describing Waves
Classwork
7.
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Waves, Light & Information
Homework
8. The highest point the wave will reach is called the crest.
9. The lowest point the wave will reach is called the trough.
10. The distance from the dotted line running through the middle of the wave to
either the crest or trough is called the amplitude.
11. The wavelength of a wave is the distance between two close crests or troughs.
It’s the distance until the wave repeats itself.
12. A wave is periodic if the wave repeats itself after a certain period of time. No
matter where you look at the wave, it looks the same.
Sound
Classwork
13. The air around you is occupied by very small objects that we call particles. You
can’t see them because they’re too small.
14. Sound moves through the air through a series of collisions.
15. In a transverse wave if the wave is moving to the left or right the particles are
moving up and down, the particles move perpendicular to the direction the
wave moves. In a longitudinal wave the particles move back and forth in the
direction that the wave is moving.
16. False: Sound is an example of a Longitudinal Wave.
Homework
17. True: Higher pitched sounds are not always louder then lower pitched sounds.
The loudness of the sound depends on the amplitude of the wave; by changing
the pitch you are only changing the frequency.
18. No, sound can’t move in outer space because sound is a longitudinal wave and
it can only move by moving stuff (it moves through a series of collisions). Since
space is completely empty, there is nothing to push, therefore sound can’t
move in space!
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Sight
Classwork
19. We need light in order to see.
20. So far we have learned that one of three things could happen to light, it can be
absorbed, bent, or reflected.
21. The sun and other light sources give off rays of light. They will continue on in
straight paths until they collide with something else.
Homework
22. We can’t see in the dark because there is no light. When you turn off the lights
you can’t see anything because there is no light to be reflected back to your
eyes allowing you to see.
23. True: We can see an object because after the light hits the object it is reflected
back to our eyes.
Color
Classwork
24. After passing a beam of white light through a prism you get the colors: red,
orange, yellow, green, blue, indigo, and violet.
25.
True: All of the colors are contained within a beam of white light.
26. False: The color we see is the color that is reflected by the object.
Homework
27. The color that we see is reflected off the object, this is why we see that color
opposed to the rest of them.
28. A box appears red because it reflects the color red and absorbs the rest of the
other colors.
29.
If nothing is reflected off the object, you see it as black.
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Mirrors
Classwork
30. False: Light being reflected off the surface of a mirror will leave at the same
angle that it hit the mirror.
31. The object will appear 5 meters behind the mirror.
Homework
32. The beam of light will take path 2, after striking the first mirror it will leave at the
angle it hit it. That beam will then bounce off of the other mirror.
Refraction
Classwork
33. When you place an object in water it appears to have bent.
Homework
34. The ruler or object appears to have bent because the light coming from
beneath the water has bent. Light passing from one material to another will
cause light to bend.
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35. The bending of light when it passes from one material to another is referred to
as refraction.
Digitized Information
Classwork
36. Your speech, a sound wave, is converted into an electrical signal, an electrical
wave that can then be transmitted from one phone to another. Afterwards that
signal gets converted back into a sound wave which the person your on the
phone with hears.
37. It would be easier to just talk with the person.
38. It would be much easier to call them on the phone or chat on the computer; it
would take too much time and money to fly to Europe to talk with them!
Homework
39. The string of numbers is 101010101.
40.
41.
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