Pattern 1 — Action-Reaction Pair (Conceptual, ~1 mark) Tested almost every year. Four options with force pairs. Only one satisfies "different bodies." Eliminate options where both forces act on the same object. Time: 15 seconds.

Pattern 2 — Apparent Weight in Lift (Numerical, 1 mark) Given: mass, lift acceleration. Find: scale reading. Use W' = m(g ± a). Trap: confusing "moving up" with "accelerating up" — a decelerating upward lift has downward acceleration, so W' = m(g − a). Time: 30 seconds.

Pattern 3 — Self-Adjusting Static Friction (Mixed, 1 mark) Given: block on surface, an applied force, μ_s and μ_k. Find: friction force. Step 1: compute μ_s N. Step 2: compare with $F_{applied}$. If $F_{applied}$ < μ_s N → $f_s$ = $F_{applied}$ (block does not move). Time: 20 seconds.

Pattern 4 — Inclined Plane with Friction (Numerical, 1 mark) Critical: N = mg cos θ. Friction = μ_k mg cos θ. Net force along incline = mg sin θ − μ_k mg cos θ. Watch for whether the block accelerates up or down the incline. Time: 45 seconds.

Pattern 5 — Atwood Machine (Numerical, 1 mark) Use the formula directly: a = ($m_{1}$−$m_{2}$)$\frac{g}{m_{1}+m_{2}}$, T = 2m_{1}$$m_{2}$$\frac{g}{m_{1}+m_{2}}. Verify T is between $m_{2}$g and $m_{1}$g. Time: 30 seconds.

Pattern 6 — Centripetal Force Source (Conceptual, 1 mark) Identify which real force provides the inward centripetal acceleration in a given scenario. Friction on flat road, N-component on banked road, tension for circular string motion. Time: 20 seconds.

High-yield tip: Patterns 1 and 3 are the most-tested conceptual traps. Patterns 2 and 5 are the most-tested numericals. Always attempt these first in the exam to secure easy marks.