Pearson International A Level Physics Unit 1: Mechanics and Materials

Pearson Edexcel International A Level Physics Unit 1 is an externally assessed written unit. This note follows the official specification content and keeps theory ownership separate from the dedicated practical-skills hub. Experimental evidence can appear inside theory questions, but Units 3 and 6 remain the written practical-skills papers. Pearson's 2025 addendum also requires confident conversion between giga, mega, kilo, centi, milli, micro and nano prefixes.

Official unit scope

1. Motion and vectors. Use uniformly accelerated motion equations; interpret displacement-time, velocity-time and acceleration-time graphs; resolve vectors; and treat horizontal and vertical projectile motion independently when air resistance is neglected.
2. Forces, momentum and energy. Draw free-body diagrams, apply Newton's laws, moments and momentum conservation, and connect work, kinetic energy, gravitational potential energy, power and efficiency without assuming that mechanical energy is always conserved.
3. Materials. Use density and upthrust, apply Stokes' law only under its stated laminar-flow conditions, and distinguish stiffness from Young modulus through force-extension and stress-strain behaviour, elastic limits and strain energy.

The content is assessed through unfamiliar contexts as well as direct recall. Build explanations from first principles: identify the system, name the relevant quantities or structures, state the mechanism, connect cause to observation and limit the conclusion to the evidence supplied. A list of keywords is not a causal explanation.

Core reasoning and methods

• Draw a vector or force diagram before resolving components and keep the sign convention consistent.
• Choose a conservation law only after defining the system and external interactions.
• Distinguish stiffness from Young modulus: one depends on specimen geometry, the other characterises material behaviour in the linear region.

Quantitative work should begin with the governing relationship, followed by unit conversion, substitution, calculation and a reasonableness check. Keep additional significant figures during working and round at the end. Qualitative work needs the same discipline: compare like with like, identify a control or baseline, and distinguish an observed result from an inferred mechanism.

Graphs and tables are arguments in compressed form. Read axes, units, uncertainty indicators and scales before describing a trend. A valid conclusion identifies the relevant interval, direction and evidence. If data scatter or overlap weakens the claim, say so. Extrapolation beyond the measured range requires justification.