Physics Notes

Physics GCE ‘O’ Level Notes ©2019 Wesley Chew Kok Sim / Sim Shang En 1 Contents Chapter 1 Measurement ......................................................................................................................... 2 Chapter 2 Kinematics .............................................................................................................................. 4 Chapter 3 Forces ..................................................................................................................................... 7 Chapter 4 Mass, Weight and Density .................................................................................................... 10 Chapter 5 Turning Effect of Forces ....................................................................................................... 11 Chapter 6 Energy, Work and Power ...................................................................................................... 12 Chapter 7 Pressure ................................................................................................................................ 14 Chapter 8 Heat ...................................................................................................................................... 16 Chapter 9 Kinetic Model of Matter ....................................................................................................... 17 Chapter 10 Transfer of Thermal Energy ................................................................................................ 18 Chapter 11 Thermal Properties of Matter ............................................................................................ 20 Chapter 12 Light .................................................................................................................................... 23 Chapter 13 Waves ................................................................................................................................. 28 Chapter 14 Electromagnetic Waves ...................................................................................................... 30 Chapter 15 Sound ................................................................................................................................. 32 Chapter 16 Static Electricity .................................................................................................................. 34 Chapter 17 Current Electricity .............................................................................................................. 36 Chapter 18 D.C. Circuits ........................................................................................................................ 38 Chapter 19 Practical Electricity ............................................................................................................. 40 Chapter 20 Magnetism ......................................................................................................................... 42 Chapter 21 Electromagnetism .............................................................................................................. 44 Chapter 22 Electromagnetic Induction ................................................................................................. 47

Physics GCE ‘O’ Level Notes ©2019 Wesley Chew Kok Sim / Sim Shang En 2 Chapter 1 Measurement *A physical quantity is a quantity that can be measured. It consists of a numerical magnitude and a unit. Base Quantity SI Unit Symbol for SI unit Length Metre m Mass Kilogram kg Time Second s Electric Current Ampere A Thermodynamic temperature Kelvin K Luminous intensity Candela cd Amount of substance Mole mol Factors Prefix Symbol 109 Giga G 106 Mega M 103 Kilo k 10−1 Deci d 10−2 Centi c 10−3 Mili m 10−6 Micro µ 10−9 Nano n Radius of a hydrogen nucleus 10−15m, size of an atom 10−10 m, width of human hair 10−4m, diameter of wire 10−3m, radius of the earth 106m. When it is a positive zero error, read the Vernier scale from left to right, and take that value and deduct it from the value of from the main scale.

Physics GCE ‘O’ Level Notes ©2019 Wesley Chew Kok Sim / Sim Shang En 3 When it is a negative zero error, read the Vernier scale from right to left, and take that value and add it to the value of from the main scale. *Each complete to-and-fro motion is one oscillation. Where the bob moves from its initial position in the picture, to the opposite end and then back to its starting position. *The period of a simple pendulum is the time taken for one complete oscillation. Intervals does not equate to the amount of oscillations.

Physics GCE ‘O’ Level Notes ©2019 Wesley Chew Kok Sim / Sim Shang En 4 Chapter 2 Kinematics *Scalar quantities are physical quantities that have only magnitude. *Vector quantities are physical quantities that have both magnitude and direction. Examples include… Scalar Vector Distance Displacement Speed Velocity Mass Acceleration Energy Force Time *Speed is the distance travelled per unit time. [SI Unit: m/s] Average Speed = 𝑇𝑜𝑡𝑎𝑙 𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑇𝑟𝑎𝑣𝑒𝑙𝑙𝑒𝑑 𝑇𝑜𝑡𝑎𝑙 𝑡𝑖𝑚𝑒 𝑡𝑎𝑘𝑒𝑛 *Velocity is the rate of change in displacement. [SI Unit: m/𝑠2] Average Velocity = 𝑇𝑜𝑡𝑎𝑙 𝐷𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑚𝑒𝑛𝑡 𝑇𝑜𝑡𝑎𝑙 𝑡𝑖𝑚𝑒 𝑡𝑎𝑘𝑒𝑛 When finding velocity, always choose a direction that will be ‘positive’ first. *Acceleration is the rate of change in velocity. [SI Unit: m/𝑠2] *Uniform acceleration is a constant rate of change in velocity. Acceleration = 𝐶ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑉𝑒𝑙𝑜𝑐𝑖𝑡𝑦 𝑇𝑖𝑚𝑒 𝑡𝑎𝑘𝑒𝑛 When an objects acceleration is decreasing, it can be known as deceleration or retardation. Uniform acceleration occurs when the change in velocity for every unit of time is the same or constant. Uniform acceleration = 𝐶ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑉𝑒𝑙𝑜𝑐𝑖𝑡𝑦 𝑇𝑖𝑚𝑒 𝑡𝑎𝑘𝑒𝑛 = 𝐹𝑖𝑛𝑎𝑙 𝑉𝑒𝑙𝑜𝑐𝑖𝑡𝑦−𝐼𝑛𝑖𝑡𝑖𝑎𝑙 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 𝑇𝑖𝑚𝑒 𝑎𝑡 𝑓𝑖𝑛𝑎𝑙−𝑡𝑖𝑚𝑒 𝑎𝑡 𝑖𝑛𝑖𝑡𝑖𝑎𝑙 Non-uniform acceleration is the opposite of Uniform acceleration. Key things to note on graphs. *The gradient of a displacement-time graph is the object’s velocity. *The gradient of a velocity-time graph is the acceleration of the object.

Physics GCE ‘O’ Level Notes ©2019 Wesley Chew Kok Sim / Sim Shang En 5 *Area under velocity-time graph is the object’s displacement. Explanation of graphs will be required, describe the graphs according to its gradient and talk about the objects motion. Displacement-Time Graph types. [Talk about Graph’s gradient then Velocity] Object is at rest [Graph gradient is zero, the object’s displacement is constant] Object is travelling with uniform velocity [Graph has a constant gradient; displacement increases every X second] Object is travelling with increasing velocity [Graph has an increasing gradient, velocity is increasing] Object is travelling with decreasing velocity [Graph has a decreasing gradient, velocity is decreasing] Velocity-Time Graph types. [Talk about velocity then acceleration] 1. Object is at rest [The velocity remains at 0, object has 0 acceleration] 2. Object is travelling at uniform velocity [Velocity stays at X, object has 0 acceleration] 3. Object is travelling with uniform acceleration or deceleration [The velocity increases or decreases at a constant rate of X, gradient is positive or negative and constant, acceleration or deceleration is constant] 4. Object is travelling with increasing acceleration. [Velocity is increasing at an increasing rate, gradient is positive and increasing, the acceleration is increasing.] 5. Object is travelling with decreasing acceleration. [Velocity is increasing at a decreasing rate, gradient is positive and decreasing, acceleration is decreasing.] Acceleration of gravity on earth is 10m/𝑠2 unless stated otherwise. Acceleration of objects due to gravity does not depend on their mass or size in a vacuum. (Where there is no air resistance.) The characteristics of Air Resistance

Physics GCE ‘O’ Level Notes ©2019 Wesley