Pearson Edexcel International GCSE in Physics · 4PH1 · Free · no account needed
Topic 1 · Forces and motion
How things move and what changes their motion: speed and acceleration, the two motion graphs, Newton's laws, weight, stopping distances, springs, momentum and moments.
Every lesson here ends the same way: learn it, teach it to an AI pupil who asks the awkward question, then defend it against the thinker with the strongest claim on it — free · no account needed.
10 lessons, covering 33 specification statements.
What you need to know — the 33 statements, and where each one is taught
Every statement this topic carries, in the specification's own numbering, with Incandio's restatement of what it asks and the lesson that discharges it. Tick them off against your own copy of the specification: this is the topic's revision checklist, not a summary of it. Incandio is aligned to this specification. It is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording — the statement numbers are given so you can check every lesson against your own copy.
| Statement | What it asks | Taught in |
|---|---|---|
| 1.1 | Use the units kg, m, m/s, m/s², N, s and N/kg | Speed, and What a Distance–Time Graph Is Telling You |
| 1.3 | Plot and explain distance–time graphs | Speed, and What a Distance–Time Graph Is Telling You |
| 1.4 | Use the relationship between average speed, distance moved and time taken | Speed, and What a Distance–Time Graph Is Telling You |
| 1.5 (practical) | Practical: investigate the motion of everyday objects such as toy cars or tennis balls | Speed, and What a Distance–Time Graph Is Telling You |
| 1.6 | Use the relationship between acceleration, change in velocity and time taken | Acceleration and the Velocity–Time Graph |
| 1.7 | Plot and explain velocity–time graphs | Acceleration and the Velocity–Time Graph |
| 1.8 | Determine acceleration from the gradient of a velocity–time graph | Acceleration and the Velocity–Time Graph |
| 1.9 | Determine distance travelled from the area under a velocity–time graph | Acceleration and the Velocity–Time Graph |
| 1.10 | Use v² = u² + 2as | Acceleration and the Velocity–Time Graph |
| 1.11 | The effects of forces between bodies: changes in speed, shape or direction | Forces, Vectors and Scalars |
| 1.12 | Identify different types of force, such as gravitational or electrostatic | Forces, Vectors and Scalars |
| 1.13 | How vector quantities differ from scalar quantities | Forces, Vectors and Scalars |
| 1.14 | Force is a vector quantity | Forces, Vectors and Scalars |
| 1.15 | Calculate the resultant of forces acting along a line | Resultant Force, Friction and F = ma |
| 1.16 | Friction as a force that opposes motion | Resultant Force, Friction and F = ma |
| 1.17 | Use F = m × a | Resultant Force, Friction and F = ma |
| 1.18 | Use W = m × g | Weight and Terminal Velocity |
| 1.21 | The forces on falling objects, and why they reach terminal velocity | Weight and Terminal Velocity |
| 1.19 | Stopping distance as thinking distance plus braking distance | Stopping Distance |
| 1.20 | Factors affecting stopping distance: speed, mass, road condition and reaction time | Stopping Distance |
| 1.22 (practical) | Practical: investigate how extension varies with applied force for springs, wires and rubber bands | Hooke's Law and Elasticity |
| 1.23 | The initial linear region of a force–extension graph and Hooke's law | Hooke's Law and Elasticity |
| 1.24 | Elastic behaviour as recovery of original shape after the deforming force is removed | Hooke's Law and Elasticity |
| 1.2 | Use the units newton metre and kilogram metre/second | Momentum |
| 1.25 | Use p = m × v | Momentum |
| 1.26 | Use momentum to explain safety features | Momentum |
| 1.27 | Use conservation of momentum to calculate mass, velocity or momentum | Conservation of Momentum |
| 1.28 | Use force = change in momentum ÷ time taken | Conservation of Momentum |
| 1.29 | Understand Newton's third law | Conservation of Momentum |
| 1.30 | Use moment = force × perpendicular distance from the pivot | Moments and Centre of Gravity |
| 1.31 | The weight of a body acts through its centre of gravity | Moments and Centre of Gravity |
| 1.32 | Use the principle of moments for a simple system of parallel forces | Moments and Centre of Gravity |
| 1.33 | How the upward forces on a supported light beam vary with the position of a heavy object | Moments and Centre of Gravity |
The lessons
- Speed, and What a Distance–Time Graph Is Telling You — Speed as a rate, the units physics insists on, and how to read a journey straight off a graph. (1.1, 1.3, 1.4, 1.5)
- Acceleration and the Velocity–Time Graph — What acceleration actually measures, why its unit looks strange, and how one graph gives you both acceleration and distance. (1.6, 1.7, 1.8, 1.9, 1.10)
- Forces, Vectors and Scalars — What a force actually does, why some quantities need a direction to mean anything, and why that makes a force one of them. (1.11, 1.12, 1.13, 1.14)
- Resultant Force, Friction and F = ma — Why a moving object stops, what really happens when you add forces up, and the one equation that connects force to motion. (1.15, 1.16, 1.17)
- Weight and Terminal Velocity — What weight actually is, why it is not the same as mass, and what happens to a falling object once the air starts pushing back. (1.18, 1.21)
- Stopping Distance — Why a car does not stop when you decide to stop it — and which of the two distances each factor actually lengthens. (1.19, 1.20)
- Hooke's Law and Elasticity — Why a spring stretches in proportion to the force — until, quite suddenly, it does not. (1.22, 1.23, 1.24)
- Momentum — Why a slow lorry is harder to stop than a fast bicycle — and why every safety device ever designed does the same one thing. (1.2, 1.25, 1.26)
- Conservation of Momentum — The bookkeeping rule that survives every collision — and why a force is really a rate of change of momentum. (1.27, 1.28, 1.29)
- Moments and Centre of Gravity — Why a spanner works better when it is longer, where an object's weight can be said to act, and how two supports share a load. (1.30, 1.31, 1.32, 1.33)
Beyond the specification: Forces, Gravity & the Scientific Revolution — the story-first course behind this topic, for curiosity rather than the exam.