E rotacional
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The rotational energy calculator (E = ½·I·ω²) determines the kinetic energy associated with an object's rotational motion. It applies a core physics formula linking moment of inertia (I) and angular velocity (ω). This tool is essential for mechanical engineering, physics, and rotational dynamics studies.
It operates using E = ½·I·ω², where I represents the object's resistance to rotation (mass distribution-dependent) and ω is angular velocity in radians per second. Input moment of inertia and rotation values to obtain energy in joules.
Ideal for calculating energy in systems like turbines, engines, vehicle wheels, and rotating components. Common precautions include checking unit consistency (don't mix RPM with rad/s) and ensuring the moment of inertia is correctly calculated for the specific axis of rotation.
Inaccurate results may arise from modeling errors (e.g., treating a solid cylinder as hollow) or ignoring friction losses. Always verify the formula's simplifying assumptions in your specific application context.
Frequently asked questions
What is rotational energy?
It's the kinetic energy from an object's rotational motion, calculated by multiplying moment of inertia by the square of angular velocity, divided by two.
How to calculate manually?
Use E = ½·I·ω², substituting moment of inertia (I) and angular velocity (ω) values in correct units.
What units should I use?
Moment of inertia in kg·m², angular velocity in rad/s. Result will be in joules (J). Convert units if needed.
When should I use this calculator?
For systems with rotational motion like turbines, engines, or any object rotating around a fixed axis.
What if results are inconsistent?
Check: 1) Correct units, 2) Moment of inertia value for the specific axis, 3) Angular velocity converted to rad/s.