A2 CIE Physics: Measurements and Errors

Here are the study notes for A2 CIE Physics, covering all topics:

Measurements and Errors

• Types of errors:
  • Random errors: unpredictable and average out to zero
  • Systematic errors: consistent and occur in the same direction
• Types of measurements:
  • Direct measurements: measured directly using instruments
  • Indirect measurements: calculated from direct measurements
• Errors in measurements:
  • Absolute error: difference between measured and true values
  • Relative error: absolute error as a fraction of true value
  • Percentage error: relative error multiplied by 100

Mechanics

• Kinematics:
  • Displacement: change in position
  • Velocity: rate of change of displacement
  • Acceleration: rate of change of velocity
• Dynamics:
  • Force: push or pull that causes acceleration
  • Newton's First Law: inertia, object at rest stays at rest, object in motion stays in motion
  • Newton's Second Law: F = ma, force is proportional to acceleration
  • Newton's Third Law: every action has an equal and opposite reaction
• Momentum:
  • Linear momentum: product of mass and velocity
  • Conservation of linear momentum: total momentum remains constant in closed systems
• Energy:
  • Kinetic energy: energy of motion
  • Potential energy: energy of position or stored energy
  • Conservation of energy: total energy remains constant in closed systems

Oscillations and Waves

• Oscillations:
  • Simple harmonic motion (SHM): oscillation about a fixed point
  • Amplitude: maximum displacement from equilibrium
  • Period: time taken for one oscillation
  • Frequency: number of oscillations per second
• Waves:
  • Types: mechanical, electromagnetic
  • Characteristics:
    • Wavelength: distance between two consecutive points in phase
    • Frequency: number of oscillations per second
    • Speed: distance traveled per second
  • Superposition: combining waves to form a new wave
  • Interference: superposition of waves with same frequency and amplitude

Thermal Physics

• Temperature:
  • Celsius scale: water freezes at 0°C, boils at 100°C
  • Kelvin scale: absolute zero at 0 K, water freezes at 273 K, boils at 373 K
• Heat transfer:
  • Conduction: direct contact between particles
  • Convection: circulation of fluids
  • Radiation: electromagnetic waves
• Internal energy:
  • Total energy of a system
  • Changes with temperature
• Specific heat capacity:
  • Energy required to change temperature by 1°C
  • Different for different substances

Electricity

• Electric charge:
  • Positive and negative charges
  • Like charges repel, opposite charges attract
• Electric field:
  • Force per unit charge
  • Direction of force on a positive charge
• Electric potential:
  • Voltage: potential difference between two points
  • Electric potential energy: energy associated with a charge in an electric field
• Resistance:
  • Opposition to flow of electric charge
  • Dependent on material, length, and cross-sectional area
• Ohm's Law: V = IR, voltage is proportional to current

Atomic Physics

• Atomic structure:
  • Protons: positive charge, in nucleus
  • Neutrons: no charge, in nucleus
  • Electrons: negative charge, orbit nucleus
• Energy levels:
  • Discrete energy levels in atoms
  • Energy changes when electrons jump between levels
• Ionization energy: energy required to remove an electron
• Radiation:
  • Types: alpha, beta, gamma
  • Ionizing and non-ionizing radiation

Nuclear Physics

• Radioactivity:
  • Spontaneous emission of radiation from nuclei
  • Types: alpha, beta, gamma
• Half-life:
  • Time for half of nuclei to decay
  • Exponential decay
• Nuclear reactions:
  • Fission: splitting of heavy nuclei
  • Fusion: combining of light nuclei
• Binding energy: energy required to separate nucleus into individual nucleons

Measurements and Errors

• Errors can be classified into two types:
  • Random errors, which are unpredictable and average out to zero
  • Systematic errors, which are consistent and occur in the same direction
• Measurements can be classified into two types:
  • Direct measurements, which are measured directly using instruments
  • Indirect measurements, which are calculated from direct measurements
• Errors in measurements have three types:
  • Absolute error, which is the difference between the measured and true values
  • Relative error, which is the absolute error as a fraction of the true value
  • Percentage error, which is the relative error multiplied by 100

Mechanics

• Kinematics:
  • Displacement is the change in position
  • Velocity is the rate of change of displacement
  • Acceleration is the rate of change of velocity
• Dynamics:
  • A force is a push or pull that causes acceleration
  • Newton's First Law states that an object at rest stays at rest, and an object in motion stays in motion, unless acted upon by an external force
  • Newton's Second Law states that force is proportional to acceleration, and is expressed as F = ma
  • Newton's Third Law states that every action has an equal and opposite reaction
• Momentum:
  • Linear momentum is the product of mass and velocity
  • The conservation of linear momentum states that the total momentum remains constant in closed systems
• Energy:
  • Kinetic energy is the energy of motion
  • Potential energy is the energy of position or stored energy
  • The conservation of energy states that the total energy remains constant in closed systems

Oscillations and Waves

• Oscillations:
  • Simple harmonic motion (SHM) is an oscillation about a fixed point
  • Amplitude is the maximum displacement from equilibrium
  • Period is the time taken for one oscillation
  • Frequency is the number of oscillations per second
• Waves:
  • There are two types of waves: mechanical and electromagnetic
  • Characteristics of waves include:
    • Wavelength, which is the distance between two consecutive points in phase
    • Frequency, which is the number of oscillations per second
    • Speed, which is the distance traveled per second
  • Superposition is the combination of waves to form a new wave
  • Interference is the superposition of waves with the same frequency and amplitude

Thermal Physics

• Temperature:
  • The Celsius scale has water freezing at 0°C and boiling at 100°C
  • The Kelvin scale has absolute zero at 0 K, water freezing at 273 K, and boiling at 373 K
• Heat transfer:
  • Conduction occurs through direct contact between particles
  • Convection occurs through the circulation of fluids
  • Radiation occurs through electromagnetic waves
• Internal energy:
  • It is the total energy of a system
  • It changes with temperature
• Specific heat capacity:
  • It is the energy required to change the temperature of a substance by 1°C
  • It is different for different substances

Electricity

• Electric charge:
  • Positive and negative charges exist
  • Like charges repel, and opposite charges attract
• Electric field:
  • It is the force per unit charge
  • The direction of the force on a positive charge is the direction of the electric field
• Electric potential:
  • Voltage is the potential difference between two points
  • Electric potential energy is the energy associated with a charge in an electric field
• Resistance:
  • It is the opposition to the flow of electric charge
  • It is dependent on the material, length, and cross-sectional area
• Ohm's Law states that voltage is proportional to current, and is expressed as V = IR

Atomic Physics

• Atomic structure:
  • Protons have a positive charge and are found in the nucleus
  • Neutrons have no charge and are found in the nucleus
  • Electrons have a negative charge and orbit the nucleus
• Energy levels:
  • Discrete energy levels exist in atoms
  • Energy changes when electrons jump between levels
• Ionization energy is the energy required to remove an electron
• Radiation:
  • There are three types of radiation: alpha, beta, and gamma
  • Radiation can be ionizing and non-ionizing

Nuclear Physics

• Radioactivity:
  • It is the spontaneous emission of radiation from nuclei
  • There are three types of radiation: alpha, beta, and gamma
• Half-life:
  • It is the time for half of the nuclei to decay
  • It follows an exponential decay pattern
• Nuclear reactions:
  • Fission is the splitting of heavy nuclei
  • Fusion is the combining of light nuclei
• Binding energy is the energy required to separate a nucleus into individual nucleons