Length matters
A longer string gives a longer period, so each swing takes more time.
Physics Learning Tool
Simple Pendulum Simulator
Change length, mass, starting angle, gravity, and damping to see how a simple pendulum swings.
Big idea: Try changing only the bob mass. The energy in joules changes, but the period estimate stays the same. Length and gravity control the timing much more strongly.
1.50 m
Longer pendulums swing more slowly.
1.00 kg
Mass changes energy size, but not the ideal period.
25 deg
Larger angles swing a little differently from the small-angle formula.
9.81 m/s^2
Weaker gravity makes the pendulum swing more slowly.
0.03 s^-1
Damping slowly removes mechanical energy.
Period estimate2.47 s
Frequency0.40 Hz
Mass effectenergy only
Potential energy0 J
Kinetic energy0 J
Total energy left100%
T ≈ 2π√(L/g)This period estimate does not include mass. That is the key discovery.
What to try
- Double the mass and watch the period stay the same.
- Make the string longer and watch the swing slow down.
- Increase damping and watch total energy shrink.
What learners should notice
Mass does not set timing
For an ideal simple pendulum, changing the bob mass does not change the period.
Energy changes form
Energy moves between potential energy at the sides and kinetic energy near the bottom.
Practice keywords
Use this simulator to explore simple pendulum period, pendulum length, gravity, damping, and energy transfer.
simple pendulumpendulum periodpotential energykinetic energyangle vs time graph