AQA A-Level Physics Paper 1 Overview

Particle Physics

• Classification of Particles:

  • Hadrons: Made up of quarks. Include baryons (3 quarks) and mesons (2 quarks).
  • Leptons: Fundamental particles. Include electrons, muons (heavier electrons), and neutrinos (no charge). Neutrinos can be electron or muon neutrinos.
  • Antiparticles: Each particle has an antiparticle equivalent with opposite charge and baryon number.

• Quarks:

  • Types: Up (+2/3 e), Down (-1/3 e), Strange (-1/3 e, strangeness = -1).
  • Baryon number for quarks = 1/3.
  • Examples: Neutrons (udd), Protons (uud).

• Mesons:

  • Types: Pions (no strangeness), Kaons (have strangeness).

Forces

• Electromagnetic Force: Affects charged particles. Exchange particle is the photon.
• Weak Nuclear Force: Affects all particles. Exchange particles are W+, W-, and Z0 bosons.
• Strong Nuclear Force: Affects hadrons. Exchange particles are pions or gluons. Holds nuclei together.
• Gravity: Exchange particle is the graviton.

Conservation Laws

• Conservation in Interactions: Charge, baryon number, and lepton numbers must be conserved.
• Beta Decay: Neutron decays into proton; involves down quark changing to up quark.

Quantum Phenomena

• Photoelectric Effect: Demonstrates light's particle nature (photons).
• Pair Production & Annihilation: Mass-energy equivalence, creation and destruction of particles.

Atomic Models

• Energy Levels: Discrete energy levels, excitation, de-excitation.
• Spectra:
  • Emission spectrum: Shows wavelengths emitted by a substance.
  • Absorption spectrum: Shows wavelengths absorbed by a substance.

Electromagnetic Spectrum

• Radiation Types: Gamma rays (from nucleus), emitted in radioactive decay.
• Ionizing Radiation: Can cause cancer by ionizing cells.

Waves

• Wave Properties:

  • Characteristics: amplitude, wavelength, frequency.
  • Speed of light changes in different media.
  • Refraction and reflection principles.

• Polarization: Light can be polarized using filters.

Electricity and Magnetism

• Ohm’s Law: V = IR, relationship between voltage, current, and resistance.
• Series Circuits: Voltage shared, current constant, total resistance is sum of all resistances.
• Parallel Circuits: Same voltage across branches, current is shared.

Quantum Mechanics

• Dual Nature of Light: Evidence from photoelectric effect and diffraction patterns.
• De Broglie Wavelength: λ = h/p, particles exhibit wave properties.

Nuclear Physics

• Radioactive Decay: Types include alpha, beta, gamma radiation.
• Half-Life: Time taken for half the radioactive nuclei to decay.

Mechanics

• Newton’s Laws:

  • First Law: Objects in motion remain in motion unless acted upon by an external force.
  • Second Law: F = ma, relationship between force, mass, and acceleration.
  • Third Law: For every action, there is an equal and opposite reaction.

• Momentum and Collisions: Conservation of momentum in collisions.

Circular Motion

• Centripetal Force: Acts towards the center of the circle.
• Angular Velocity: ω = 2π/T, frequency of rotations.

Simple Harmonic Motion (SHM)

• Conditions: Restoring force proportional to displacement.
• Equations for SHM: T = 2π√(m/k) for springs, T = 2π√(L/g) for pendulums.

Thermodynamics

• Energy Transfers: Work done, heat transfer.
• Laws of Thermodynamics: Principles governing energy conservation.

This summary covers the main concepts and equations necessary for understanding AQA A-Level Physics Paper 1, with a focus on particle physics, quantum phenomena, electromagnetism, wave properties, nuclear physics, and classical mechanics.