Kinetic Energy Calculator
Kinetic Energy Calculator:
Updated 13/11/26
Robodojo operate a 200J max KE for spinning weapons at their Featherweight Sportsman events.
DRG & GRA operate 1kJ max KE for beetles, 2kJ max for feathers.
Calculations:
Mass (g) = (Volume / 1000) x Density (g/cm³)
Bar
Volume (mm³) = Length × Width × Thickness (all in mm)
Moment of Inertia at Centre of Mass (g·mm²) = (1/12) x Mass x (Length² + Width²)
Disc
Volume (mm³) = π x Radius² x Thickness (both in mm)
Moment of Inertia at Centre of Mass (g·mm²) = (1/2) x Mass x Radius²
Cylinder
Volume (mm³) = π x (Outer Radius² – Inner Radius²) x Length / Height (all in mm)
Moment of Inertia at Centre of Mass (g·mm²) = (1/2) x Mass x (Outer Radius² + Inner Radius²)
Teeth
Volume (mm³) = Length × Width × Thickness (all in mm)
Moment of Inertia at Centre of Mass (g·mm²) = Tooth Count x ((1/12) x Tooth Mass x (Length² + Width²))+(Tooth Mass x Offset Distance²)
Kinetic Energy
Angular Velocity (rad/s) = RPM x 2π / 60
Kinetic Energy (kJ) = (1/2) x (Total Axis Moment of Inertia x 10⁻⁹) x Angular Velocity² / 1000
Inspired by the Team Cosmos Calculator
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