IGCSE Physics Lecture Notes

Introduction

• The video aims to provide comprehensive coverage of the CIE IGCSE Physics syllabus.
• Perfect answers are provided throughout the video for exam success.
• Revision guides are available for purchase on the speaker's website.

Measurement Techniques

Volume

• Measured using a measuring cylinder.
• Not precise; read the volume at the meniscus.

Length

• Use a meter ruler for long items; centimeter ruler for smaller items.
• Measurements in millimeters, centimeters, meters.

Time

• Use a clock, stopwatch, or stop clock.
• Digital clocks can measure to the nearest hundredth of a second.

Calculations

Average Value

• For distance: Measure multiple times, sum the results, and divide by the number of measurements.
• For time: Measure multiple times, sum the times, and divide by the number of measurements.

Pendulum

• Time period is the time taken for one oscillation.
• Measure time for several swings, then divide by the number of swings for accuracy.

Forces

Resultant Force

• Combined effect of all forces acting on an object.
• Defined as a single force with the same effect as all the actual forces.

Parallelogram of Forces

• Not always necessary to use.
• Example: Calculate resultant force by adding or subtracting forces according to their direction.

Force Examples

• Pulling a pulley (350N) against a weight (300N) results in 50N upwards.
• Two men pushing with forces in the same direction, add the forces.

Speed, Distance, and Time

Equations

• Distance = Speed x Time
• Speed = Distance / Time
• Time = Distance / Speed
• Use formula triangles to remember equations.

Graphs

• Distance-time graphs: Speed is distance divided by time.
• Flat line indicates stationary period.
• Velocity-time graphs: Acceleration is change in speed over time.

Acceleration and Free Fall

• Deceleration is negative acceleration.
• Free fall due to gravity is constant at 9.8 m/s² without air resistance.
• Terminal velocity: Balance of weight and air resistance.

Mass and Weight

• Weight = Mass x Gravitational Field Strength.
• Mass is constant, weight varies with gravity.
• Units: Weight in Newtons (N), Mass in kilograms (kg).

Density and Pressure

Density

• Density = Mass / Volume
• Measure mass using a balance; volume using displacement for irregular objects.

Pressure

• Pressure = Force / Area
• Larger area results in lower pressure.

Motion and Forces

Friction

• Opposes motion and generates heat.
• Friction varies with surface texture.

Circular Motion

• Requires centripetal force.
• Objects moving in a circle are constantly accelerating towards the center.

Hooke's Law

• Extension of a spring is proportional to the force applied up to the elastic limit.
• Beyond the elastic limit, springs are permanently deformed.

Moments

• Moment = Force x Distance from pivot.
• Principle: Clockwise moments equal anti-clockwise moments for equilibrium.

Momentum

Definition

• Momentum = Mass x Velocity
• Momentum is conserved in closed systems.

Calculations

• Recoil velocity and momentum before/after collisions.

Energy

Types of Energy

• Chemical, Kinetic, Gravitational, Elastic, Nuclear, Thermal, Magnetic, Electrostatic.

Conservation

• Energy cannot be created or destroyed, only transformed.

Work Done

• Work involves a force causing movement.

Power

• Power is the rate of doing work.

Efficiency

• Efficiency = (Useful Energy Out / Total Energy In) x 100%
• Use Sankey diagrams to represent energy transfers.

Waves

Types

• Transverse (e.g., light) and Longitudinal (e.g., sound).

Properties

• Frequency, wavelength, amplitude.
• Wave speed = Frequency x Wavelength.

Reflection and Refraction

• Incident angle equals reflection angle.
• Refraction involves change in wave speed and direction.

Electromagnetic Spectrum

• Radio, Microwaves, Infrared, Visible Light, Ultraviolet, X-rays, Gamma rays.
• Uses and dangers of each part of the spectrum.

Electricity

Circuit Components

• Symbols and functions of various circuit components.

Current and Voltage

• Current is the flow of charge; voltage is the energy per unit charge.

Resistance

• Resistance opposes current flow; measured in ohms.
• V = IR (Ohm’s Law), resistance depends on material, length, and cross-sectional area.

Power and Energy

• Power = Voltage x Current.
• Energy = Power x Time.

Safety

• Earth wires, fuses, and circuit breakers protect from electrical faults.

Radioactivity

Types of Radiation

• Alpha, beta, gamma: Properties, penetration, and applications.

Half-life

• Time taken for half the radioactive nuclei to decay.
• Used in dating and medical applications.

Astronomy

Solar System

• Planets, moons, and their orbits.

Stars and Galaxies

• Life cycle of stars; Big Bang Theory; evidence supporting it.

Universe

• Expanding universe; galaxies moving apart.
• Use of redshift and background radiation in astronomy.

Conclusion

• Summary of key points and reminder about revision guides.