Learn how invisible forces squeeze and pull at every part of a bridge—and why understanding them is the key to building structures that don't collapse
Part of Build A Bridge That Holds 100 Coins
Educational content slides
Every bridge is constantly at war with gravity.
Two types of forces are always present but completely invisible:
Both forces exist simultaneously in every bridge, fighting each other to a standstill.
Understanding these invisible forces = designing structures that don't collapse.
Test your understanding with this quiz.
You place a heavy book on a simple plank bridge between two desks. What force is the TOP surface of the plank experiencing?
Complete this exercise and get AI-powered feedback.
Now that you understand compression and tension, look at the world differently. Every structure around you is a force-management system.
Think about: Where are forces concentrated? How does the structure handle them? What materials are used where?