Physics

Kinetic Energy of a Pendulum Calculator

Find a pendulum's speed and kinetic energy at the bottom of its swing.

Mass

Length

Release angle (°)

Gravity (m/s²)

Calculated Output

Kinetic energy at bottom (J) 1.314

Speed at bottom 1.621

Formula: KE = m·g·L·(1 − cosθ)

Step-by-Step Breakdown

1. Values used:

2. Mass = 1

3. Length = 1

4. Release angle = 30 °

5. Gravity = 9.81 m/s²

7. Kinetic energy at bottom = 1.314J

8. Speed at bottom = 1.621

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The math behind it

The height drop is L(1 − cosθ). All that potential energy m·g·h becomes kinetic energy at the bottom.

1 kg, 1 m, 30° → about 1.31 J, 1.62 m/s.

Where is speed greatest?

At the bottom of the swing, where height is lowest.