Find your rhythm
Pendulum explorer
Change length and gravity to discover what controls a pendulum’s period.
Pendulum explorerTRY IT YOURSELF
Period2.006 s
Frequency0.498 Hz
Angle now-10 °
Length1 m
Teal + amber · follow the changing valuesIdealized physics model
What if you changed…
Try a starting point
Make the pendulum twice as slow. How much longer must it be?
See the calculation
T = 2π√(L/g)
- T = 2π√(L/g) = 2π√(1/9.81) = 2.01 s.
- Frequency = 1/T = 0.498 Hz.
- Small-angle motion: θ(t) = 10 cos(2πt/T) degrees.
What this model assumes
Small-angle approximation, massless rod/string, point bob, no damping. Angles are limited to 15°.
Keep an eye on this
Large swings have a longer period than the small-angle approximation predicts.
Understand the physics ↗A little question. A clearer picture.
Pendulum explorer: common questions
Wondering about the why? Start here.
Does a heavier bob swing faster?
Not in this ideal pendulum model: mass cancels out. Length and gravity set the small-angle period.
Why does amplitude barely change the period?
The formula assumes small angles. The animation follows that approximation; for large angles, amplitude does affect period.