Playbook
Laws of Motion
47 q - 1.04/paper - 11% HARD. One free-body diagram per body; momentum and collisions are the cheap page.
- Questions in the bank
- 47
- q/paper (2024–25 papers)
- 1.04
- Tagged HARD
- 11%
- Subtopics
- 3
Strand: Quick-Win
When you’ll see it
Blocks connected by strings, a lift accelerating, a force on a body for a short time, or two bodies colliding.
How this chapter is tested
47 q at 1.04 a paper, 11% HARD. Impulse, Momentum, and Collisions is the cheap page (17 q, 6%): impulse = change of momentum, momentum is conserved in every collision, and kinetic energy only in an elastic one.
Newton's Laws — Force, Tension, Lift, and Connected Blocks (25 q, 12%) is one method: draw each body alone, mark every force on it, write F = ma for each, and solve together. A person in a lift accelerating upward reads m(g + a) on a scale.
The same method runs through Rotational Dynamics (banked roads, the vertical circle) and Oscillations (a block on springs), so the hours here pay in two cornerstone chapters.
The sub-skills
The distinct skills inside the chapter, in the order to learn them.
Free-body diagrams
One diagram per body, every force marked, F_net = ma for each; connected blocks share the acceleration.
Apparent weight
In a lift: up-accelerating m(g + a), down-accelerating m(g − a), free fall zero.
Impulse and collisions
Impulse = Δp = F Δt. Momentum conserved always; KE only if elastic. Coefficient of restitution e = separation speed / approach speed.
Traps to expect
Distractor shapes this chapter reuses. The Traps page covers the patterns that cut across chapters.
Conserving kinetic energy in every collision
Only elastic collisions conserve KE. Bodies that stick together lose some; momentum alone gives the common speed.
Applying e to the height
e scales the speed. A ball dropped from h rebounds to e²h, not eh.
Learn it before you drill it
This chapter has full teaching notes — foundations, worked examples, self-checks and a per-subtopic mastery checkpoint. Read the notes once, then drill subtopic by subtopic below.
Laws of Motion notesDrill every laws of motion question
47 questions from the bank, scoped to 3 bundled subtopics.
Drill one subtopic at a time
The 3 subtopics this playbook covers, in catalog order.
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