The Strong Bones of a Skyline: teacher key

How Buildings Stand Up, grade 5 edition, written for 5th grade. Squeezing, stretching, swaying and a swinging weight: how engineers keep towers standing against weight and wind.

Read the book. Print this page for the key.

Questions and answers

1. What happens when a beam bends?
   • Both sides stretch
   • One side squeezes and the other stretches (answer)
   • Both sides squeeze
2. What is reinforced concrete?
   • Concrete with glass
   • Concrete with steel bars inside (answer)
   • Concrete mixed with sand
3. What does Otis's safety brake do if the rope breaks?
   • A spring grabs a ratchet (answer)
   • A door locks
   • The elevator speeds up
4. Why do engineers watch sway?
   • It breaks elevators
   • It makes buildings heavier
   • People on high floors can feel it (answer)
5. Why did the Home Insurance Building have masonry over its frame?
   • To make it taller
   • To hold the elevator
   • To protect the metal from fire (answer)

Words

• masonry: stone or brick
• compression: squeezing force
• tension: stretching force
• truss: triangle frame
• pendulum: swinging weight
• foundation: building's base