Science
Angular momentum.
Definition
Angular momentum is the rotational equivalent of linear momentum, describing how much rotational motion an object has. It depends on the object's moment of inertia and angular velocity, and it is conserved in a closed system with no external torques.
Examples
Real-world.
- 1 A figure skater spins faster by pulling their arms in, decreasing moment of inertia while conserving angular momentum
- 2 Earth's angular momentum keeps it spinning at a nearly constant rate on its axis
- 3 A spinning gyroscope resists changes to its orientation due to conservation of angular momentum
Key Fact
L = Iω; angular momentum is conserved when net external torque = 0.