Tubes, Towers and Shaking Ground: teacher key

How Buildings Stand Up, grade 6 edition, written for 6th grade. From stone walls to hollow-tube towers and rubber bearings, see how engineers answer weight, wind and earthquakes.

Read the book. Print this page for the key.

Questions and answers

1. What was Fazlur Khan's idea?
   • Use only wood
   • Put the strong parts in the outside walls (answer)
   • Add more elevators
2. What is a base isolator made of?
   • Concrete only
   • Wood and glass
   • Rubber and lead (answer)
3. What do steel bars do inside concrete?
   • Take the stretching (answer)
   • Make it dry
   • Make it lighter
4. How did engineers straighten the Leaning Tower of Pisa?
   • Pulled it with ropes
   • Removed soil from beneath its north side (answer)
   • Added tall walls
5. Why does a base isolator help in an earthquake?
   • It stops the wind
   • It adds floors
   • The building moves less when the ground shakes (answer)

Words

• masonry: stone or brick
• tension: stretching force
• pendulum: swinging weight
• isolator: shaking blocker