CIE Physics IGCSE: Summary Notes for General Physics

Measurement Tools

• Length and Time
  • Ruler: Measures length from 1mm to 1m.
  • Micrometer Screw Gauge: Measures very small distances.
  • Measuring Cylinder: Determines volume of irregular objects via water displacement.
  • Clocks: Analogue and digital devices for measuring time intervals.

Motion

• Speed and Velocity

  • Speed: Distance traveled per unit time.
  • Velocity: Speed in a given direction.

• Acceleration

  • Defined as the rate of change of velocity.
  • Acceleration of free fall near Earth is constant.

• Graph Interpretations

  • Distance-Time Graph
    • Gradient represents velocity.
    • Horizontal line indicates stationary.
    • Curved line indicates acceleration.
  • Speed-Time Graph
    • Gradient represents acceleration.
    • Area under line is distance traveled.
    • Curved line indicates changing acceleration.

Mass and Weight

• Mass: Measure of matter in an object, resists change in motion.
• Weight: Gravitational force on a mass, measured in Newtons.
• Gravity: Earth’s gravitational field strength is around 10 N/kg.
• Free Fall: Acceleration due to gravity is about 10 m/s².

Density

• Definition: Mass per unit volume.
  • Formula: ( \text{Density} = \frac{\text{mass}}{\text{volume}} )
• Measurement Techniques
  • Liquids: Measure mass difference of filled vs. empty cylinder.
  • Solids: Use dimensions or water displacement for irregular shapes.
• Water's Density: 1 g/cm³; objects denser will sink, less dense will float.

Forces

• Newton’s Laws of Motion

  • First Law: Constant velocity unless acted upon by a resultant force.
  • Second Law: ( F = ma )
  • Third Law: Equal and opposite reactions.

• Friction and Air Resistance: Impede motion and cause heating.

• Circular Motion: Constant speed with changing direction, resulting in acceleration.

Deformation

• Elastic Deformation: Object returns to original shape.
• Plastic Deformation: Object permanently deforms.
• Hooke’s Law: ( F = kx )

Moments and Equilibrium

• Moment of Force: Turning effect; ( \text{Moment} = \text{force} \times \text{distance} )
• Equilibrium Conditions: Balance of clockwise and anticlockwise moments.

Centre of Mass

• Definition: Point where mass is considered to act.
• Stability: Depends on the position relative to suspension point.

Scalars and Vectors

• Scalar: Magnitude only.
• Vector: Magnitude and direction.
• Examples:
  • Scalars: Distance, Speed, Time
  • Vectors: Displacement, Velocity, Acceleration

Momentum

• Definition: Product of mass and velocity ( p = mv ).
• Impulse: Change in momentum, ( \text{Impulse} = F\Delta t ).
• Conservation: Total momentum before and after a collision is equal.

Energy, Work, and Power

• Energy Forms: Kinetic, gravitational potential, etc.
• Work: Energy transfer when a force moves an object.
• Power: Rate of energy transfer or work done.
• Efficiency: Ratio of useful work output to total energy input.

Energy Sources

• Renewable: Biofuel, Wind, Solar, etc.
• Non-renewable: Fossil fuels, Nuclear; more reliable but environmentally harmful.

Pressure

• Definition: Force per unit area.

• Measurement Examples:

  • Barometer: Atmospheric pressure.
  • Manometer: Pressure difference between gases.

• Pressure in Liquids: Increases with depth and density, ( P = \rho gh ).

These notes provide a comprehensive overview of key concepts in general physics relevant to the CIE IGCSE curriculum.