Mechanical systems (AS91524) is a 6-credit external — the biggest single standard at Level 3 Physics. It extends Level 2 mechanics into four connected areas:
- Translational motion — the centre of mass, and momentum and impulse in two dimensions.
- Circular motion and gravity — objects moving in a circle under two or more forces, plus Newton's law of gravitation and satellites.
- Rotating systems — spinning objects: torque, rotational inertia, and angular momentum.
- Oscillating systems — simple harmonic motion, from pendulums and springs to resonance.
Two things to fix in your mind before you start:
- You don't memorise formulas. Every relationship is printed on a resource sheet in the exam. The marks are for choosing the right one and explaining the physics.
- g=9.81 m s⁻² at Level 3 (not 9.8 as at Level 2) — it's stated in the assessment specification. Bring a calculator, ruler, and protractor, keep unrounded values through a calculation, and round only the final answer.