Simulators & plain answers
See it move, then believe it.
Drag the thing, feel the law. Every answer here is written twice: once for an eight-year-old, once for the full picture. And each one comes with a small machine you can poke at until it makes sense.
FIG. V — THE PENDULUM LAW
String length 1.2 m
Gravity Earth · 9.8 m/s²
Period (one full swing)
2.20s
Swings per minute
27.3/min
Try to cheat: swing it high, swing it low — the time per swing barely changes. Make
the string longer and it slows right down. The pendulum only listens to its string
and its planet.
The simulators · 32 plates live
Why is the sky blue? →Why are sunsets red? →How rainbows form →How shadows work →Reflection in mirrors →Refraction in water →The magnifying glass →Why ice floats →Why hot air rises →Air pressure →Bicycle gears →Levers →Pulleys →Inclined planes →Friction →Momentum →Inertia →Projectile motion →Pendulums →Sound waves →Why do we have seasons? →Why does the Moon change shape? →How does a circuit work? →Electromagnets →Binary numbers →Logic gates →States of matter →The pH scale →Ecosystems →Human senses →The Pythagorean theorem →Probability →How do we see colour? →
Section I · Everyday Physics · all twenty →
I · Light & Colour
II · Heat & Air
III · Simple Machines
IV · Motion & Forces
The seven sections
There are two hundred questions on the list. They ship a few at a time, and only once they're worth sending to a friend.
— ;colony