Physics Grade 12 · Exam Revision

Physics · Grade 12 · Exam Revision Date: Top Journal

Every distinction begins with one topic at a time.- start now

1. Exam Format & Cognitive Levels
2. Vectors, Forces & Newton's Laws
🔒 3. Momentum and Impulse
🔒 4. Vertical Projectile Motion
🔒 5. Work, Energy and Power
🔒 6. Doppler Effect
🔒 7. Electrostatics
🔒 8. Electric Circuits
🔒 9. Electrodynamics
🔒 10. Photoelectric Effect & Atomic Spectra
🔒 11. Condensed Reference
🔒 12. Exam Strategy & Mark-Maximising Technique
🔒 Journal
🔒 Wellbeing
🔒 Planner

BEFORE YOU WRITE · HOW PAPER 1 IS BUILT EXAM FORMAT

Learning outcomes · you must be able to

State the total marks, the duration and the content groups of Paper 1, the Physics paper.
Explain how the multiple-choice QUESTION 1 and the structured questions after it share the 150 marks.
Rank the nine Physics topics by mark weighting, so revision time reaches the heaviest topics first.
Quote the cognitive-level split for this paper and explain what it implies about how to study.
Apply the marking rules for a calculation, and the four exam golden rules, on every question rather than only the hard ones.

📖 KEY DEFINITION QUESTION 1: the multiple-choice opener, ten subquestions numbered 1.1 to 1.10 at 2 marks each, so 20 marks, sampled across every Physics topic. QUESTION 2 onward: the remaining 130 marks, built from longer structured questions in one continuous numbering run that ends at QUESTION 10, each usually drawn from one topic or from a deliberate pairing of two related topics. Subquestion numbering never goes deeper than three digits, so 2.1.1 is the finest grain you will ever see.

There are no lettered sections in this paper. Several revision aids still print an "A" part and a "B" part, but the real paper carries no section letter anywhere: the questions simply run 1, 2, 3 and on to 10.

Paper 1 at a glance

Item	Paper 1, Physics
Total marks	150
Duration	3 hours, so 180 minutes
Sections	none; QUESTION 1 is the multiple-choice question, then QUESTIONS 2 to 10 are structured
QUESTION 1	ten subquestions, 1.1 to 1.10, at 2 marks each = 20 marks
QUESTIONS 2 to 10	130 marks of structured questions
Content groups	Mechanics 65, Electricity and magnetism 55, Waves sound and light 15, Matter and materials 15
Topics examined	Newton's laws and vectors, momentum and impulse, vertical projectile motion, work energy and power, the Doppler effect, electrostatics, electric circuits, electrodynamics, the photoelectric effect with atomic spectra
Data sheet supplied	the physics sheet only: Table 1 constants and Table 2's five formula blocks
Marked	externally, per step, with positive marking between subquestions

⚡ MUST MEMORISE

Paper 1 is Physics: 150 marks, 3 hours, no lettered sections. QUESTION 1 is ten multiple-choice subquestions at 2 marks each = 20 marks, then QUESTIONS 2 to 10 carry the other 130. Content is never restricted by the term it was taught in, so a Term 1 topic is exactly as examinable as a Term 3 topic, in the Preliminary paper and in the Final. Paper 2 examines the Chemistry half of the subject in a separate 150-mark sitting with its own data sheet, and is covered by the companion Chemistry pack, so the two papers together make up the 300-mark subject total.

How the marks divide across cognitive levels

Cognitive level	Share of Paper 1	Marks, roughly	Typical instruction
Remember	15%	about 23	define, state, name, write down the formula
Understand	35%	about 53	explain, describe, interpret a graph, compare two situations
Apply / Analyse	40%	about 60	calculate in a new context, analyse a circuit or a v-t graph, deduce
Evaluate / Create	10%	about 15	judge whether a conclusion is valid, improve an investigation, design a method

⚠️ COMMON MISTAKE Quoting one cognitive-level split for both papers of this subject. The two papers are deliberately weighted differently, and the split printed above (15 / 35 / 40 / 10) belongs to Paper 1. Physics leans harder on Apply and Analyse than the Chemistry paper does, which is exactly why a Physics revision plan built on definitions alone underperforms even when the definitions are perfect.

🔥 FREQUENTLY TESTED The split itself is never asked about, yet it explains the whole shape of the paper: with 40% of the marks at Apply and Analyse, most questions hand you an unfamiliar scenario and expect a familiar method. That is why past-paper practice moves a Physics mark far more than re-reading a formula list does.

Mark weighting by topic · where the 80/20 rule points

The four content-GROUP totals are the national planning weights the examiners build the paper to, so they hold year after year. The split within a group is reconstructed from two recent sittings, which means an individual paper can move a mark or two either way, never enough to change the revision order. The table sums to exactly 150.

Paper 1 topic	Marks	Weight	Priority
Electric Circuits (with internal resistance)	23	15%	Highest single question on the paper
Vectors, Forces and Newton's Laws	18	12%	High
Vertical Projectile Motion (1D)	17	11%	High
Electrostatics	17	11%	High
Work, Energy and Power	16	11%	High
Doppler Effect	15	10%	Medium
Electrodynamics	15	10%	Medium
Photoelectric Effect & Atomic Spectra	15	10%	Medium
Momentum and Impulse	14	9%	Medium
Total	150	100%	QUESTION 1's 20 MCQ marks come OUT of these rows

Grouped officially: Mechanics 18 + 14 + 17 + 16 = 65, Electricity and magnetism 17 + 23 + 15 = 55, Waves sound and light 15, Matter and materials 15. Percentages are rounded to whole numbers, so the column reads 99. QUESTION 1 never gets its own row, because its 20 marks are sampled out of the topic rows above rather than added to them: add them twice and a 150-mark paper looks like a 170-mark one, and every topic percentage comes out too small.

⭐ EXAM FAVOURITE Mechanics as a cluster is 65 of the 150 marks, more than the whole electricity group and nearly half the paper. Secure that cluster and a large share of the total is already protected. After it, go straight at the single biggest question on the paper: electric circuits with internal resistance at 23 marks.

⚠️ COMMON MISTAKE Ranking electrostatics above electric circuits because it feels like the harder topic. Circuits carries 23 marks against electrostatics at 17, so circuits is the bigger investment. In the same way, electrodynamics is not the thin, throwaway topic it is often treated as: at 15 marks it carries exactly as much as the Doppler effect and the photoelectric effect do.

⚠️ COMMON MISTAKE Assuming a Term 3 topic such as electrodynamics can be dropped because it did not appear in the most recent June paper. It stays fully in scope at full weighting for the Preliminary and the Final. A June absence usually reflects the school calendar, never a syllabus exclusion. June durations and totals are set by the school or province in any case, so nothing about a June paper defines the national format.

Typical question-to-topic mapping

Question	Usual topic	Group
Q1 (1.1 to 1.10)	multiple choice, 2 marks each, sampling every topic on the paper	all four
Q2	vectors, forces and Newton's laws	Mechanics
Q3	vertical projectile motion in one dimension	Mechanics
Q4	momentum and impulse	Mechanics
Q5	work, energy and power	Mechanics
Q6	the Doppler effect, sound and red shift	Waves, sound and light
Q7	electrostatics, Coulomb's law and electric fields	Electricity and magnetism
Q8	electric circuits, almost always with internal resistance	Electricity and magnetism
Q9	electrodynamics, machines and alternating current	Electricity and magnetism
Q10	the photoelectric effect and atomic spectra	Matter and materials

The ORDER above is stable: two recent sittings ran exactly this spine. What moves year to year is the marks per question and how many questions a topic is split across, so plan around the topic order and never promise yourself a fixed mark per question number.

Investigation skills are examined in the written paper

Practical work is assessed inside the school, but the SKILLS of an investigation are examinable in Paper 1 itself, and the Physics contexts they are set in come straight from the prescribed work. The Term 3 Physics experiment has two parts: determining the internal resistance of a battery, then building a series-parallel network from known resistors, measuring its equivalent resistance with an ammeter and a voltmeter, and comparing that with the theoretical value. Those are exactly the two contexts the circuits question keeps returning to.

Skill the paper asks for	What earns the mark
Formulate the investigative question	name the independent and the dependent variable in one sentence, phrased as a question
Write a hypothesis	a testable statement predicting a direction of change, never a question and never "I think"
Identify the variables	independent (what you change), dependent (what you measure), controlled (what you deliberately keep constant)
List apparatus	the specific instrument, not "equipment": ammeter, voltmeter, rheostat, connecting wires, cell
Justify repeating the reading	repeated trials reduce the effect of random error, so an average is more reliable
State a precaution	open the switch between readings so the cell does not warm and its internal resistance drift
Draw and read the graph	V against I for the internal-resistance experiment: the gradient's magnitude is r and the V-intercept is the emf
Evaluate a conclusion	say whether the DATA supports it, and name the specific measurement that does or does not

💡 EASY MARK Writing the correct formula down before substituting is very often its own method mark, even when a later arithmetic step falls over. QUESTION 1 costs nothing extra to answer well either: one line per subquestion, no working needed, straight to the option letter, and each of the ten is a full 2 marks. Twenty marks in roughly fifteen minutes is the best rate on the paper.

The marking rules, stated as rules

A calculation is marked step by step, not as one block, so knowing where the individual marks sit changes how you write. Every rule below applies to this paper.

Rule	Consequence
Marks are given for the correct formula, the correct substitution, and the answer with its unit	three separate places to earn marks in one calculation
An inappropriate formula scores zero, however perfect the substitutions	choosing the right equation is the first real mark
A substitution error inside a correct formula	formula and substitution marks kept, the remaining marks lost
No formula written but the substitutions all correct	one mark forfeited
Substitutions must appear INSIDE the formula	a list of values above the formula risks the substitution mark
Changing the subject of a formula carries no mark in itself	write the formula in its data-sheet form first, then rearrange
A formula written with no calculation attempted	no formula mark either
Round the final answer to at least two decimal places unless told otherwise	one decimal place is at risk
Units belong on the final answer	a correct number without its unit loses the answer mark
Two answers given and neither struck out	only the FIRST is marked, even if the second is the right one
Positive marking between subquestions	a wrong value carried forward correctly still earns the later marks, but it does not rescue a slip made inside a single multistep subquestion

Worked example · where the five marks actually sit (invented for practice)

Q: A 4 kg block is pulled along a rough horizontal surface by a 30 N force parallel to the surface. The frictional force is 10 N. Calculate the acceleration. (5)

F_net = ma formula, mark 1

Taking the direction of motion as positive: F_net = 30 + (−10) = 20 N correct net force, mark 2

20 = (4)a substitution inside the formula, mark 3

a = 5,00 m·s⁻² value, mark 4

in the direction of the applied force direction on a vector answer, mark 5

∴ only two of the five marks depend on the arithmetic. Writing F_net = ma and the net-force line banks two marks before a single calculator key is pressed, which is exactly why a blank answer is the most expensive thing you can write.

The four exam golden rules

⚡ MUST MEMORISE · the four golden rules

RTQ, Read The Question: underline the command word and every given value before writing a line of working. Show your workings: formula first, then the substitution inside it, then the final line, because each step is marked separately. Units and direction: a unit on every measured quantity and a stated direction on every vector answer. Check: reserve the last few minutes for units, directions, rounding, and confirming every subquestion has an answer written down.

A syllabus feels enormous only until you know exactly which fraction of it the marks actually live in.- on reading the mark weighting before the content

ONE-MINUTE SUMMARY

Paper 1 is the Physics paper: 150 marks over 3 hours with no lettered sections. QUESTION 1 is ten multiple-choice subquestions worth 20 marks, then QUESTIONS 2 to 10 carry the other 130. Officially the marks group as Mechanics 65, Electricity and magnetism 55, Waves sound and light 15 and Matter and materials 15, exactly 150, and the biggest single question is electric circuits at 23 marks with Newton's laws next at 18. This paper's cognitive spread is 15% remember, 35% understand, 40% apply and analyse and 10% evaluate and create, which is why practising unfamiliar scenarios beats re-reading formulas. Calculations are marked per step, so write the formula, substitute inside it, round the final answer to at least two decimal places, attach the unit and give vectors a direction, and strike out any attempt you do not want marked, because only the first answer is read.

IN THE EXAM

Spend the first few minutes skimming QUESTION 1 through QUESTION 10, noting each one's topic and mark allocation. Do not waste a second hunting for a lettered section divider, because there is none.
Use the mark weighting table to decide, before the exam, how much of the study time each remaining topic still deserves; 23 marks of circuits outrank 15 marks of Doppler.
Underline the command word in every question. A "calculate" answered like a "state", or the reverse, is one of the commonest ways capable learners lose marks they actually knew.
Write something for every subquestion. The formula alone is a mark, and a blank line is the only guaranteed zero on the paper.

Paper 1 · Mechanics · 18 marks

MECHANICS CLUSTER · TOPIC 1 OF 4 (65 MARKS TOTAL) VECTORS, FORCES & NEWTON'S LAWS

What you must be able to do

Draw a fully labelled free-body diagram for each object before writing a single equation.
Resolve the weight of an object on an incline into its mg sinθ and mg cosθ components.
Find the normal force from the perpendicular equilibrium condition instead of assuming it equals mg.
Test the driving component against the maximum static friction to decide whether the object slides, before using kinetic friction.
Set up one F net = ma equation per object for two masses connected by a string over a pulley, then combine them.
Combine two forces acting at angles into a single resultant, giving both magnitude and direction.
Calculate the gravitational force between two masses using Newton's Law of Universal Gravitation, measuring d from centre to centre.

Where the 18 marks come from

One free-body diagram plus one F_net = ma equation per object: the single most repeated calculation in this topic, worth 4 to 8 marks whenever a slope, friction or a connected pulley system shows up.
Resolving weight into slope components (mg sinθ / mg cosθ): a near-guaranteed opening sub-question, usually 2 to 3 marks on its own.
Stating a law in words, or classifying a quantity as vector or scalar: reliable 1 to 2 mark bookwork with zero calculation risk.
A universal gravitation calculation: a smaller, standalone 3 to 4 mark sub-question, rarely folded into the rest of this topic.

📖 KEY DEFINITION Vector: a quantity with both magnitude and direction (force, weight, velocity, momentum). Scalar: magnitude only (mass, distance, speed, energy). Newton's First Law: an object stays at rest or at constant velocity unless a non-zero resultant force acts on it. Newton's Second Law: the resultant force on an object equals its mass times the acceleration it produces, in the direction of that resultant. Newton's Third Law: if object A exerts a force on object B, object B exerts an equal, opposite force back on A. Newton's Law of Universal Gravitation: any two masses attract each other with a force proportional to the product of their masses and inversely proportional to the square of the distance between their centres.

Core content · the slope toolkit (≈4 to 6 marks whenever a slope appears)

Quantity	Formula	Typical mark cost
Parallel component (drives motion down the slope)	F_g∥ = mg sinθ	2 marks: formula line + substitution
Perpendicular component (presses into the surface)	F_g⊥ = mg cosθ	2 marks
Normal force	from vertical equilibrium - NOT automatically mg	1 mark, only if correctly justified

Core content · the three laws, formula-sheet form

Law	Core idea	Formula form
1st (inertia)	no change in motion without a resultant force	ΣF = 0 → a = 0
2nd	a is proportional to F, inversely proportional to m	F_net = ma
3rd	every force has an equal, opposite reaction on the OTHER object	F_{A on B} = −F_{B on A}

Static friction only grows as large as needed to prevent sliding, capped at f_s(max) = μ_sN. Kinetic friction is constant once sliding starts: f_k = μ_kN. Always test the maximum before assuming an object moves.
Connected objects (a string over a pulley, or two blocks in contact): one free-body diagram and one F_net = ma equation per object, then combine the equations - they share the same magnitude of acceleration and the string carries the same tension throughout.

⚡ MUST MEMORISE

F_net = ma
F_g = mg
f_s(max) = μ_sN and f_k = μ_kN
F = Gm₁m₂⁄d²
g = GM⁄d², with G = 6,67×10⁻¹¹ N·m²·kg⁻² (given on the data sheet, never derived)

⭐ EXAM FAVOURITE A combined slope question: test maximum static friction to show whether the object slides, then calculate acceleration with kinetic friction, often extended into a connected two-mass system over a pulley. This combination is worth 10 to 14 marks in one structured question and is close to guaranteed on Paper 1 every year.

🔥 FREQUENTLY TESTED Resolving weight on a slope, deciding static versus kinetic friction, and writing one F_net = ma equation per object in a connected system - these three skills reappear across almost every structured Mechanics question, not only this topic.

⚠️ COMMON MISTAKE F_N is not automatically mg - the moment a slope or an extra vertical force is present, find F_N from perpendicular equilibrium instead. A Newton's third law pair can never appear together in one object's free-body diagram, since the two forces act on different objects. Mixing up sinθ and cosθ on a slope loses easy marks - always sketch the angle rather than guess.

💡 EASY MARK "Is quantity X a vector or a scalar?" and "state Newton's first/second/third law in words" (1 to 2 marks each, no calculation needed) appear on almost every paper and should never be missed.

Worked example 1 · Friction test and Newton's second law on a slope (7 marks)

Q: A 38 kg crate rests on a ramp inclined at 22° to the horizontal. The coefficient of static friction is 0,40; the coefficient of kinetic friction is 0,32. (a) Show whether the crate slides down under gravity alone. (b) Calculate its acceleration once sliding.

F_g∥ = mg sinθ = (38)(9,8)(sin22°) = 372,4 × 0,37461 ≈ 139,50 N

F_N = F_g⊥ = mg cosθ = 372,4 × 0,92718 ≈ 345,28 N

Maximum static friction = μ_sN = (0,40)(345,28) ≈ 138,11 N

Since 139,50 N > 138,11 N, the driving component just exceeds the maximum available static friction, so the crate slides.

Once sliding: f_k = μ_kN = (0,32)(345,28) ≈ 110,49 N (up the slope)

F_net = F_g∥ − f_k = 139,50 − 110,49 ≈ 29,01 N down the slope

F_net = ma → a = 29,01 ÷ 38 ≈ 0,76 m·s⁻² down the slope

∴ The crate slides, accelerating at about 0,76 m·s⁻² down the incline

Worked example 2 · Connected objects over a pulley (6 marks)

Q: Block A (10 kg) sits on a rough horizontal table (μ_k = 0,22) and is connected by a light inextensible string, over a frictionless pulley, to a hanging Block B (6 kg). Calculate the system's acceleration and the string tension.

Block B (vertical): m_Bg − T = m_Ba → 58,8 − T = 6a

Block A (horizontal): T − f_k = m_Aa, where f_k = μ_km_Ag = (0,22)(10)(9,8) = 21,56 N

So T − 21,56 = 10a

Adding the two equations to eliminate T: 58,8 − 21,56 = 16a → 37,24 = 16a → a ≈ 2,33 m·s⁻²

Substituting back: T = 10(2,33) + 21,56 ≈ 44,8 N

∴ The system accelerates at about 2,33 m·s⁻², with a string tension of about 44,8 N

Worked example 3 · Universal gravitation, a quick standalone calculation (3 marks)

Q: Calculate the gravitational force of attraction between the Earth (mass 5,97×10²⁴ kg) and a 1 500 kg satellite orbiting at 6,8×10⁶ m from the Earth's centre.

F = Gm₁m₂⁄d² = (6,67×10⁻¹¹)(5,97×10²⁴)(1 500) ÷ (6,8×10⁶)²

= (5,97×10¹⁷) ÷ (4,62×10¹³)

∴ F ≈ 1,29×10⁴ N

Worked example 4 · Resultant of two forces at angles (4 marks)

Q: Two cables pull on a boulder. Cable 1 exerts 50 N at 35° above the horizontal, up and to the right. Cable 2 exerts 38 N at 60° above the horizontal on the other side, up and to the left. Calculate the magnitude and direction of the resultant force.

Taking right as positive x and up as positive y:

F_1x = 50cos35° ≈ 40,96 N, F_1y = 50sin35° ≈ 28,68 N

F_2x = −38cos60° = −19,00 N, F_2y = 38sin60° ≈ 32,91 N

ΣF_x = 40,96 − 19,00 = 21,96 N ΣF_y = 28,68 + 32,91 = 61,59 N

R = √(21,96² + 61,59²) ≈ 65,4 N

θ = tan⁻¹(61,59 ÷ 21,96) ≈ 70,4° above the horizontal, toward the side where ΣF_x is positive

∴ The resultant is about 65,4 N at 70,4° above the horizontal

Memory aid: "FBD before formulas" - sketch and label every force on the object before writing a single equation. On a slope, remember the component ALONG the surface always pairs with sinθ, and the component INTO the surface always pairs with cosθ, provided θ is measured from the incline itself - sketch the little right-angle triangle every time instead of guessing which ratio to use.

A force that never appears in your diagram can still cost you the mark - draw first, calculate second.- on free-body diagrams

Why it matters: the most repeated calculation here is one free-body diagram plus one F net = ma equation per object. Test the driving component against the maximum static friction before assuming anything moves, or you will calculate a neat acceleration for a crate that is standing still.

🧠 ACTIVE RECALL

Which of the following is a scalar quantity?(2)

A skater glides across smooth ice at a constant velocity. What can you conclude about the resultant force acting on the skater?(2)

A 9 kg block rests on a frictionless horizontal table with no other vertical force applied. The normal force on the block is closest to:(2)

If the distance between two point masses is tripled, the gravitational force between them becomes:(2)

A hammer strikes a nail, driving it into a plank. The Newton's third law reaction pair to the force of the hammer on the nail is:(2)

A gentle push, too small to move it, is applied to a large filing cabinet. The static friction acting on the cabinet is:(2)

Which one of the following would INCREASE the kinetic friction force acting on a block sliding across a rough horizontal floor?(2)

A 15 kg block rests on a frictionless slope inclined at 20° to the horizontal. Calculate the component of the block's weight acting parallel to the slope.(4)

A weather satellite of mass 1 100 kg orbits 700 km above the Earth's surface. Take the Earth's mass as 5,97×10²⁴ kg and its radius as 6,38×10⁶ m. Calculate the gravitational force on the satellite, showing clearly how you find the distance d.(5)

An 8 kg trolley on a frictionless table is connected by a string over a pulley to a hanging 5 kg mass. Set up the two equations of motion and calculate the acceleration of the system and the tension in the string.(5)

Explain this for a Grade 8: what do Newton's second and third laws actually mean when you kick a ball?

ONE-MINUTE SUMMARY

Draw the free-body diagram first, every time - it is where the marks start. Resolve weight into F_g∥ and F_g⊥ on a slope, test static friction against its maximum before assuming motion, then apply F_net = ma per object. A Newton's third law pair never appears twice in the same diagram. F_N equals mg only on a flat surface with no other vertical force. Gravitation follows F = Gm₁m₂⁄d², the same inverse-square shape you will meet again this year.

IN THE EXAM

Budget 12 to 15 minutes for a full slope-plus-connected-system question worth 10 to 14 marks - it is close to guaranteed every year.
Two to four of the ten Paper 1 MCQs typically touch vectors, friction or Newton's laws directly, on top of the structured question; together they bring the topic to its 18 marks inside the 65-mark Mechanics group.
Marks are earned for a correctly labelled free-body diagram and a clearly substituted formula line, not just a final number - never skip straight to the answer.

🔒 MOMENTUM AND IMPULSE

🔒 VERTICAL PROJECTILE MOTION

🔒 WORK, ENERGY AND POWER

🔒 DOPPLER EFFECT

🔒 ELECTROSTATICS

🔒 ELECTRIC CIRCUITS

🔒

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A winner is a loser who tried one more time.- keep going, all the way to the exam