Science - Unit 2 Guide 1
Grade 7
Structural Strength and Stability
3.1 The Life Cycle of a Product
pg. 136-137
1. Explain in your own words, the 13 steps in the Production Process
2. Why is the choice of materials important when designing a new product?
3. Which of the 13 stages of the Production Process is the most important? Why?
- HOMEWORK - make a plan for your CD rack - using the Production Process
**Try This** Building with Newspaper
pg 135
- build your CD rack - using newspapers and tape
*print out the Scientific Method - found on the 'Common Drive'
3.2 Product Testing
pg. 138-139
1.Why are prototypes tested before they are mass-produced?
2. How does testing help to improve the products we use?
3. Testing a prototype can yield unexpected results. Car designers discovered they should weaken rather than
strengthen parts of the car body to improve safety. Why would an unexpected result be important? What things
should you consider if the results of your test are unexpected?
**Try This** Testing the Rack
3.7 Planned Obsolescence
pg. 150-151
1. define: planned obsolescence
2. Why aren't products designed to last forever?
3. Give three new examples of products that are designed to last a long time and products that have a short
planned life. Explain why these products have different product lives.
*DEBATE* In your groups - page 151 - read the information aloud
- As a group answer the following questions and hand in for marking.
1.When considering the points and counterpoints in the reading, What other points and counterpoints can you
think of? Explain them. (2 points and 2 counterpoints)
3.4 Stability
1. define: stability
pg. 142-145
- centre of gravity
2. In your own words, explain centre of gravity and how it affects the stability of
a structure.
3. (a) What are the support points and support base of the structures to the right?
(b) Which of the structures to the right are stable? Explain your evaluation.
3.5 Stabilizing the Tower of Pisa
pg. 146-147
1. Discuss orally with your group questions a,b,c,d,e,f that are in the reading.
2. The stones used in the foundation of the Leaning Tower are thicker than the stones used higher up. How does
this affect the stability of the tower?
3. The original architects wanted to create a tower that would stand centuries, so they chose marble as their
building material. If durability was less important, what materials could they have chosen that would have made
the tower more stable? Explain your choices.
3.8 Forces and Structures
pg. 152-153
1. define: magnitude
2. Explain: -magnitude of force
- direction of force
- point and place of application of force
3. The wind exerts a force on structures. Using the terms force, magnitude, and direction, describe how changes
in the wind might affect the structure of a tree.
3.9 Applying Force *Experiment*
pg. 154-155
*print out the Scientific Method from the 'Common Drive'
3.10 Loads
1. define: load
pg. 156-157
- static load
- dynamic loads
- dead load
-live load
2. Draw a diagram of structures that are supporting a dead load, a live load and a dynamic load. Identify the
forces that create the loads.
a) a chair
b) an apartment building
c) a running shoe as it hits the ground
**Try This** Reducing the Load
3.11 Determining Factors of Safety *Experiment*
pg. 158-159
*print out the Scientific Method from the 'Common Drive'
------------------------------------------------------------------------------------------------------------------------------Experiment: Building with Newspaper - newspapers
- tape (scotch, masking, duct, etc...)
Applying Force - 2m of string/yarn/twine, etc...
-------------------------------------------------------------------------------------------------------------------------------Dear Parent/Guardian
This is to notify you that there is a test on Unit 3 Guide 1 on Thursday January 31st 2013 (weather permitting)
Notes are due on Friday January 25th or Monday January 28th. By signing this sheet and returning it before the
test, your child will earn an extra point on their test score.
____________________________
Parent/Guardian Signature