When the Earth Shakes

1
When the Earth Shakes

• LESSON 11

2
OBJECTIVES

• Observe the formation and movement of waves in
  water.
• Use a spring to simulate different kinds of
  waves.
• Relate wave movement in a spring to earthquake
  waves.
• Using a spring to model possible damaging effects
  of earthquake waves
• Design and build a model house that is resistant
  to shaking.

3
Inquiry 11.1

• Look at the spring, the stopwatch, and the
  masking tape. How might you use these materials
  to study waves?
• What are some ways you could move the spring?

4

• Classify the drawings on pg. 123 according to
  their spring movement.
• Pull and Push (P-Wave)
• Side to Side (S-Wave)

5

• Which type of wave will move the fastest?
• P-Wave
• Which type of wave might do the most damage to
  buildings?
• B. Surface Waves

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Student Sheet 11.1Instructions

• Title Spring Test for Earthquake Motion
• Below the 2 house pictures you are to write
  P-wave or S-wave
• Number 2 asks you to draw ARROWS ON EACH HOUSE to
  show how the earthquake BODY wave might move the
  ground.
• Place tape on surface of spring. See example.

7
Handling of Springs (Otherwise known as a Slinky)

• Do NOT stretch the spring too far.
• Do NOT let go of the spring suddenly.
• Completely compress the spring before letting go
  of it.
• Do NOT play with the spring in the air, use it
  only on the floor.

8
Job Assignments for Groups

• Timer
• Recorder
• Spring Mover
• Spring Observer
• Spring Holder

9
Fair Test?

• How do you use the paper to make sure that you
  are moving the spring the same distance each
  time?
• Look at pictures on page 124 125.
• Practice a few times before you begin your
  trials.

10
P-Waves

• In one quick motion, pull the spring back the
  length of the paper and quickly push the spring
  forward ONE time. Do not let go of spring.
• Discuss observations with group.
• This is an ex. Of a P-Wave
• Make your sketch of the P-wave on Stud. Sheet
  11.1
• Conduct 3 timed trials of this and record your
  timings on your sheet.

11
S-Waves

• Turn your paper the other direction
• Test the side to side motion.
• In one quick motion, shake the spring ONE time
  from side to side, keeping it on the floor with
  in the borders of the paper.
• Do 3 timed trials of the side-to-side wave.
• (1 complete round trip hand to chair and back
  to your hand)

12
Observe Masking Tape

• Tape represents structures on earth
• Spring represents earthquake wave moving,
  throughout the body of the earth
• How does the tape move with a P-wave?
• Push and pull
• How does the tape move with an S-wave?
• Side to side

13
Reflection Questions

• A. Describe the wave each time you moved the
  spring.
• Push and Pull
• Side-to-side

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Reflection Questions cont.

• B. Look at your data. Which wave was faster
• P-wave
• C. If you could not tell which wave was faster,
  what could have occurred during the investigation
  to affect your results?
• Human error

15
Observations of Tape

• A. How did each wave affect the tape?
• P-wave
• S-wave
• Assume the tape represents houses and other
  structures on the earths surface. How does the
  ground move with each wave? Look at Fig. 11.8 on
  pg. 127