9702 · 3.2
Non-uniform motion
In Cambridge Physics, **uniform motion** means steady speed in a straight line, but **non-uniform motion** is far more common and interesting! It describes any movement where an object's **velocity** changes over time. This change, whether speeding up, slowing down, or turning, is fundamentally caused by **forces** acting upon the object. Let's delve into the principles governing these dynamic motions. This pilot aligns with **Senpai Corner** AS notes (2025–2027) for topic **3.2**.
Need to know
What you need to know
- Momentum is a vector quantity, meaning it has both magnitude and direction.
- Mass is a measure of an object's inertia – its resistance to changes in motion.
- Newton's Second Law can be rephrased: resultant force equals the rate of change of momentum ($F = \frac{\Delta p}{\Delta t}$). This is the most general form of the law, as it applies even when mass is changing (e.g., a rocket burning fuel), whereas $F=ma$ assumes constant mass.
- This definition is particularly useful when mass isn't constant or in impulse calculations.
Explanation
Non-uniform motion
- Momentum is a vector quantity, meaning it has both magnitude and direction.
- Mass is a measure of an object's inertia – its resistance to changes in motion.
- Newton's Second Law can be rephrased: resultant force equals the rate of change of momentum ($F = \frac{\Delta p}{\Delta t}$). This is the most general form of the law, as it applies even when mass is changing (e.g., a rocket burning fuel), whereas $F=ma$ assumes constant mass.
- This definition is particularly useful when mass isn't constant or in impulse calculations.