Quick revision for O Level Physics (includes radioactivity)

O LEVEL PHYSICS REVISION NOTES O LEVEL PHYSICS REVISION PREFACE: This book is prepared for Physics revision of the O level syllabus. The topics are presented in a short but accurate manner for a quick revision. No pictures or diagrams are used in this book to reduce the size. Readers should make it a point to refer back to their textbook for their reference. It is hoped that the book achieves its aim of helping readers to grasp the key facts for their revision.

O LEVEL PHYSICS REVISION NOTES CONTENTS: 1. MEASUREMENTS 2. SPEED, VELOCITY & ACCELERATION 3. FORCES 4. MOMENTS - THE TURNING EFFECTS OF FORCES 5. WORK, ENERGY & POWER 6. THERMAL EXPANSION 7. MEASUREMENT OF TEMPEARATURE 8. MELTING, BOILING & EVAPORATION 9. HEAT TRANSFER 10. WAVES - BASIC WAVE PROPERTIES 11. LIGHT 12. SOUND 13. MAGNETISM 14. STATIC ELECTRICITY 15. ELECTRICITY 16. ELECTRICAL ENERGY 17. ELECTROMAGNETIC INDUCTION 18. RADIOACTIVITY

O LEVEL PHYSICS REVISION NOTES 1. MEASUREMENTS Key notes: 1. The S.I unit for length is metre (m); for mass is kilogram (kg) and for time is seconds (s). 2. When using a ruler, try to avoid parallex and end errors. 3. The ruler can be read up to 1 decimal place in cm, e.g. 4.3cm. 4. The jaws of the vernier callipers enable us to measure the interval or external diameter of an object accurately. 5. The vernier callipers can be read up to 2 decimal places in cm, e.g. 2.34cm. A ruler can be read up to only 1 decimal place in cm, e.g. 2.3cm. 6. When reading the vernier callipers, (e.g. 2.34cm) 2.3cm is read from the main scale. 0.04cm is read from the vernier scale. 7. A micrometer screw gauge may be used to measure lengths less than 4cm. For length of 1cm to 10cm, the vernier callipers may be used. To measure length greater than 10cm, a metre rule is suitable. 8. The mass of an object is the amount of matter it contains. 9. The mass of an object is constant. 10. The period of oscillation of a simple pendulum increases as its length increases, but is independent of the amplitude of the oscillation and the mass of its bob. 11. Units for density : kg/m ³ or g/cm ³ 12. 1 g/cm ³ = 1000 kg/m ³ Formulas:  The Simple Pendulum Frequency, f = one second / period = 1 / T  Density, ρ = mass / volume

O LEVEL PHYSICS REVISION NOTES 2. SPEED, VELOCITY & ACCELERATION Key notes: 1. A scalar quantity has only a magnitude while a vector quantity has both a magnitude and a direction. 2. Speed is distance moved per unit time. It is a scalar quantity. 3. Velocity is distance moved per unit time in a particular direction. It is a vector quantity. 4. Displacement is the distance moved from a fixed point in a particular direction. 5. In a displacement-time graph, gradient = velocity. 6. For a particle moving with a constant velocity away from the observer, the gradient is a positive constant. 7. For a particle moving with a constant velocity towards the observer, the gradient is a negative constant. 8. For a particle moving with an increasing velocity away from the observe