#AP Physics 1: Angular Momentum - The Night Before 🚀

Hey! Let's get you prepped for the exam with a super focused review of angular momentum. We'll break it down, make it stick, and get you feeling confident. Let's do this!

#5.E: Conservation of Angular Momentum

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• What it is: Angular momentum is like the rotational version of linear momentum. It's all about how much 'rotational motion' something has.
• The Rule: If there's no outside twisting force (torque) acting on a system, its total angular momentum stays the same. Think of it like a spinning figure skater – when they pull their arms in, they spin faster, but the total angular momentum doesn't change.

• Formula: $L = I\omega$ where:
  • $L$ is angular momentum (kg⋅m²/s)
  • $I$ is the moment of inertia (how hard it is to rotate something)
  • $\omega$ is angular velocity (how fast something is spinning)

#Skater Example

• Initial State (Arms Out): High moment of inertia ($I$) because mass is far from the axis of rotation, lower angular velocity ($\omega$).
• Final State (Arms In): Lower moment of inertia ($I$) because mass is closer to the axis of rotation, higher angular velocity ($\omega$).
• Key Point: Angular momentum ($L$) stays constant!

#Planetary Motion

• Closed Orbits: Planets in closed orbits have constant angula...