BETA
Chapter 1
The physics of resonance
Chapter 2
Tragedies of synchronized steps
Chapter 3
The wobbly Millennium Bridge
Chapter 4
Engineering safer bridges
YOUR GOAL
Master of How marching crowds collapse bridges
Ch 1 · The physics of resonance
artiteacher Time the crowd's footsteps to learn why marching in step can collapse a bridge.
artiteacher Bridge Resonance
Out of sync, out of sync / Or the bridge is coming down!
artiteacher A marching crowd acts as a single, massive force hitting the ground in perfect unison.
artiteacher Resonance occurs when an external force repeatedly pushes an object at its natural frequency.
Fun Fact
Tacoma Narrows collapse: The 1940 Tacoma Narrows Bridge collapse was nicknamed Galloping Gertie because of its intense vertical bouncing.
Glossary
resonance (noun)
The condition in which a system vibrates with maximum amplitude at a specific natural frequency. This phenomenon caused England's Broughton Suspension Bridge to collapse in 1831 when soldiers marched across it.
The condition in which a system vibrates with maximum amplitude at a specific natural frequency. This phenomenon caused England's Broughton Suspension Bridge to collapse in 1831 when soldiers marched across it.
Quiz
What unit of measurement is used to describe the number of wave cycles or steps per second?
Quiz
What physical property determines the specific rate at which an object naturally vibrates when disturbed?
Quiz
In what year did the Tacoma Narrows Bridge in Washington collapse due to wind-induced resonance?
Quiz
Why does a marching military unit pose a greater risk to a bridge than a disorganized crowd of the same weight?
Quiz
What physics phenomenon occurs when an external force pushes an object at its natural frequency, amplifying its vibration?
Quiz
When two waves meet in phase and their peaks combine to create a larger wave, what is this called?
Quiz
What is the typical frequency range, measured in Hertz, of human footsteps during a regular march?