#AP Physics C: Mechanics - Momentum & Collisions 🚀

Hey! Let's get you totally prepped for the exam with a super-focused review of momentum and collisions. We'll break down the key concepts, hit the most important points, and make sure you're ready to tackle any question they throw at you. Let's do this!

#Conservation of Linear Momentum

#What is Momentum? 🤔

• Momentum ($\vec{p}$) is a measure of an object's motion. It's a vector, so it has both magnitude and direction.
• Formula: $\vec{p} = m\vec{v}$ (mass times velocity)

#The Big Idea: Conservation of Linear Momentum 💡

• Key Concept: In a closed system (no external forces), the total momentum remains constant. It's like a cosmic bank account – what you start with is what you end with.

• Important: This applies to the total momentum of the system, not necessarily individual objects within the system.

#Visualizing Conservation

Caption: The total momentum before an event (like a collision) equals the total momentum after the event.

#Why Does Momentum Conserve? 🤔

• It's all thanks to Newton's Third Law: For every action, there's an equal and opposite reaction. This means that when objects interact, the forces they exert on each other are equal and opposite, leading to no net change in momentum for the system.
• Impulse: Impulse ($\vec{J}$) is the change in momentum. If there's no external force, there's no impulse, and thus no change in momentum. $\vec{J} = \Delta\vec{p} = \vec{F}\Delta t$

• Think of momentum as the "oomph" of a moving object. A heavier train or faster train has more "oomph" or momentum.
• If no external force acts on the train system, its total momentum stays the same, even if the train cars bump into each other.

#Collisions

#Wha...