Physics_Notes_28.8.20

1 Physics Notes

2 Contents Chapter: Page: 1 Measurements 3 2 Kinematics 5 3 Forces 6 4 Mass, Weight and Density 8 5 Turning Effect of Forces 9 6 Energy, Work and Power 10 7 Pressure 11 8 Temperature 12 9 Kinetic Model of Matter 14 10 Transfer of Thermal Energy 15 11 Thermal Properties of Matter 17 12 Light 20 13 Waves 23 14 Electromagnetic Waves 25 15 Sound 27 16 Static Electricity 28 17 Current Electricity 31 18 D.C Circuits 33 19 Practical Electricity 35 20 Magnetism 40 21 Electromagnetism 43 22 Electromagnetic Induction 45

3 Chapter 1: Measurements Physical Quantities - Quantities that can be measured, consists of a numerical magnitude and a unit. Prefixes Prefix Symbol Standard Form Tera T 1012 Giga G 109 Mega M 106 Kilo k 103 Deci d 10-1 Centi c 10-2 Milli m 10-3 Micro μ 10-6 Nano n 10-9 Conversion of km/h to m/s - 𝑘𝑘𝑘𝑘/ℎ ÷ 3.6 = 𝑘𝑘/𝑠𝑠 Sizes of well-known objects: - Radius of Earth: 6378000m (6.378 × 106) - Size of atom: 0.0000000001m (10−10)

4 Instruments Vernier Calipers - Precision: 0.01cm - Read the main scale until the immediate left of the zero mark on the vernier scale, then add the marking which coincides with the marking on the main scale. - Zero Errors: - Positive - Zero mark of Vernier is slightly to the right of the main scale. - Negative - Zero mark of Vernier is slightly to the left. Micrometre Screw Gauge - Precision: 0.01mm - Read main scale, then read thimble reading - Zero Errors - Positive - Zero marking on thimble scale is below datum (centre) line. - Negative - Zero marking on thimble scale is above datum line. Pendulums - Oscillation - One complete to-and-fro motion (A->C->A)/(B->C->B->A->B) - Period - Time taken for one complete oscillation

5 Chapter 2: Kinematics Scalar Quantities - Quantities with only magnitude - Distance, Speed, Mass, Energy, Time Vector Quantities - Quantities with both magnitude and direction - Displacement, Velocity, Acceleration, Force Distance - Total distance travelled. Displacement - Total distance travelled in a straight line. Speed - The distance moved per unit time (m/s). Velocity - The rate of change of displacement (m/s). Acceleration - The rate of change of velocity (m/s2). - 𝑎𝑎 = 𝑣𝑣−𝑢𝑢 𝑡𝑡 Important Information - The gradient of a displacement-time graph of an object is its velocity. - The gradient of a velocity-time graph of an object is its acceleration. - The area under a velocity-time graph of an object is its displacement. - Acceleration due to Gravity = 10 m/s2

6 Chapter 3: Forces - Newton (N) Vector Diagrams - In a vector diagram, if all 3 arrows form a complete loop, the forces are in - equilibrium. - Parallelogram method - Tip-to-tail method

7 Newton’s Laws of Motion First Law - Every object will continue in its state of rest or uniform motion in a straight line unless a resultant force