Euler equations for a rigid body
Body-axis angular acceleration includes rotation of the axes.
Key knowledge
In principal axes fixed to a rigid body, Euler's equations connect torque components with angular acceleration and products of angular velocities.
Values and equations
τ_i = I_i ω̇_i + (I_k − I_j)ω_jω_k, cyclic (i,j,k)=(1,2,3)
- τ_i
- Body-axis torque component N m
- I_i
- Principal moment of inertia kg m²
- ω_i
- Body-axis angular-velocity component rad s⁻¹
Conditions and scope
- Use torques and principal moments about the centre of mass, or a fixed pivot with the appropriate inertia.
- Principal moments are constant in body axes; orientation also requires its own evolution equation.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Lecture 28 pages 1–3, equations 5 and 9–11: rotating-frame derivative and principal-axis equations.
2026-10-10 · Classical rigid-body rotational dynamics only; deforming inertia and attitude integration excluded.
Entry details
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- Structured reference record
- University reference · University core expansion