1. Changing Earth lesson 6A
Are Rocks Elastic?

2. INITIAL THOUGHTS How do moving plates change the Earth’s crust?
Why do earthquakes occur more often in some places compared to others?
How are volcanoes, earthquakes and tsunamis evidence of slow and large scale motion of the Earth’s plates?

3. INITIAL THOUGHTS DRAWINGS
Step 1- Look over the 3 different maps.
Tell your group what you notice on the maps.
Step 2 – Google the location of Kent, WA
Mark Kent on the Puget Sound area map, Western North America map and the world map.
Step 3- Predict geographical features:
Using a pencil draw triangles where you think volcanoes are.
With the same pencil shade in areas with earthquake concerns.
Draw little waves where you think tsunamis are likely to happen.

4. PART 1 Class Agenda TODAY’s PLAN: Today’s TaSK:
EQ: How can rocks be deformed? LT: Use “Cause and Effect” thinking to “Conduct an investigation” for the effects of adding energy to rocks. SC: Experiment with earthquake machine to determine if rocks are elastic.
Work with table partners for the investigation. Develop resources to use for future mapping projects.

5. Easy to change its shape
What words do you think of when you hear the term “Elastic?”
Make a concept map with “Elastic” as the topic word…
Here’s what others mentioned…
Stretchy
Flexible
Bendable
Easy to change its shape
What does Elastic mean?

6. TYPES OF ENERGY & EARTHQUAKE TERMS (RECORD DEFINITIONS IN YOUR lAb NB)
Look up one following words…
*POTENTIAL ENERGY *KINETIC ENERGY
*STRESS *FRICTION
*BRITTLE *DUCTILE
*EXTENSSION *COMPRESSION
Which words have a relationship?
Which have opposite meaning?

7. Are rocks Elastic? Class Discussion
Can you bend a rock? Why/why not?
What if another rock was pushing on it, what might happen?
Who thinks rocks are elastic? What evidence do you have?
Let’s play with a model… We’ll call it “Earthquake Machine”
(Demonstrate & have students answer on their worksheet)
How can we modify the model so that earthquakes no longer occur?
How can we modify the model to make bigger earthquakes?
What is elastic in the earth that can store energy?

8. How are the words “Brittle” and “Ductile” different?
If we made a spectrum with “Brittle” on one end and “Ductile” on the other, we could call it the “Elastic Energy Spectrum.”
Where would you place the following items if you were to consider their “Elastic Potential,” meaning how much energy can they take on and store before they reach the “Elastic Limit” and break?
BRITTLE (Elastic Potential Energy) DUCTILE
Rubber band
Wood ruler
Pencil
Paper clip
Glass
Gum
Plastic ruler
Marble tile
Rocks

9. WhaT EVIDENCE DO YOU NEED TO CHANGE YOUR MIND that rocks can be elastic?
Describe common everyday objects that bend (ELASTIC), then break (BRITTLE)? List examples on your worksheet: (Question 4) (RUBBER BAND DEMO) (MARBLE TONG DEMO)

10. COMPLETE MIDDLE CHECK
HOW ARE YOU FEELING ABOUT YOUR SUCCESS CRITERIA? HOW IS YOUR TABLE PARTNER DOING? RAISE YOUR HAND IF YOU HAVE QUESTIONS.

11. Answer WORKSHEET Questions 5-7 as a team before proceeding
When we are pushing against an object we are adding energy where we are in contact with the object. . That energy is absorbed by the object and can be stored by the object as “Potential Energy” waiting to be used.
Examples: Gasoline in a car not running, An apple waiting to be eaten
Eventually matter can only absorb so much energy before it meets its “limit.”
Q5. How much stress must build up in a pencil before it stops bending and breaks?
Q6. How much stress can a rubber band store before it breaks?
Q7. How is a pencil different than a rubber band? How are they both different compared to a rock?

12. how much added “STRESS” iS required to form these changes:
TABLE TALK: Which is an example of Brittle Rock & which is an example of Ductile rocks?
(Draw on your worksheet & Explain)

13. EXIT TICKET:
COMPLETE YOUR END CHECK & WORK ON YOUR MAPPING PROJECT

14. OPTIONAL EXTENSION: STUDY & REVIEW
Watch the following video and answer these questions:
Start video at 5:23 & Watch to the end (NOTICE THE TV & EGG)
Describe the elastic energy of skin.
Explain why a rock has more elastic energy than an egg.
Explain why balloons and bubble gum pops.
Describe how this relates to plate tectonics.