Kinetic Energy of a Pendulum Calculator

Calculate pendulum kinetic energy, potential energy, and motion parameters using physics principles

Pendulum Energy Calculator

Mass of the pendulum bob

Length from pivot to center of mass

m

Height above lowest point

m

Maximum height reached during swing

Current velocity of the pendulum

Acceleration due to gravity (m/s²)

Energy Analysis Results

0.00 J
Kinetic Energy
KE = ½mv²
0.00 J
Potential Energy
PE = mgh
0.00 J
Total Energy
E_total = mgh_max
0.00 m/s
Maximum Velocity
v_max = √(2gh_max)
0.00 m/s
Velocity from Height
v = √(2g(h_max-h))
0.000 m
Height from Velocity
h = h_max - v²/(2g)

Energy Conservation: E_total = KE + PE = constant

At maximum height: All energy is potential (PE = mgh_max, KE = 0)

At bottom: All energy is kinetic (KE = ½mv_max², PE = 0)

Energy Conservation Analysis

Example Calculation

Wrecking Ball Pendulum

Mass: 1000 kg (1 ton wrecking ball)

Length: 10 m (crane cable length)

Maximum height: 3 m above lowest point

At bottom position: Height = 0 m

Energy Calculations

Total Energy: E = mgh_max = 1000 × 9.81 × 3 = 29,430 J

Maximum Velocity: v_max = √(2gh_max) = √(2 × 9.81 × 3) = 7.67 m/s

At bottom: KE = 29,430 J, PE = 0 J

At top: KE = 0 J, PE = 29,430 J

Pendulum Motion Phases

1

Release Point

Maximum height, zero velocity

All potential energy

2

Descending

PE converts to KE

Velocity increases

3

Bottom Point

Maximum velocity, zero height

All kinetic energy

4

Ascending

KE converts back to PE

Velocity decreases

Energy Conservation

Total Energy

E = KE + PE = constant

Kinetic Energy

KE = ½mv²

Potential Energy

PE = mgh

Maximum Velocity

v_max = √(2gh_max)

Physics Tips

Energy is conserved in ideal pendulum motion

Maximum velocity occurs at the bottom

Period depends only on length and gravity

Real pendulums lose energy to air resistance

Understanding Pendulum Energy

What is a Pendulum?

A pendulum is a weight (called a bob) hanging from a pivot point that can swing freely. In the mathematical pendulum approximation, we ignore friction and the mass of the string/rod, focusing on the physics of energy transformation.

Energy Conservation Principle

The total mechanical energy of a pendulum remains constant during its motion. Energy continuously transforms between kinetic energy (energy of motion) and potential energy (energy due to height).

Applications

  • Pendulum clocks for timekeeping
  • Wrecking balls for demolition
  • Seismometers for earthquake detection
  • Amusement park rides

Key Formulas

Energy Equations

  • Kinetic Energy: KE = ½mv²
  • Potential Energy: PE = mgh
  • Total Energy: E = KE + PE = constant
  • Maximum Velocity: v_max = √(2gh_max)

Motion Parameters

  • Period: T = 2π√(L/g)
  • Frequency: f = 1/T
  • Angular Displacement: θ = arccos((L-h)/L)

Note: These equations assume no friction or air resistance. Real pendulums gradually lose energy due to these factors.