Title Physics Notes - Rafael DE COLE.pdf ✅

CONTENTS 1. GENERAL PHYSICS ······················································································1 1.1. Quantity and Unit··········································································· 1 1.2. Length and Time ············································································ 2 1.3. Speed, Velocity and Acceleration························································· 4 1.4. Mass and Weight···········································································10 1.5. Volume and Density ·······································································12 1.6. Force·························································································13 1.7. Moment ·····················································································16 1.8. Work, Energy and Power ·································································18 1.9. Simple Machines···········································································22 2. THERMAL PHYSICS···················································································· 25 2.1. Kinetic theory ··············································································25 2.2. Thermal properties·········································································27 2.3. Gas laws ····················································································30 2.4. Transfer of thermal energy································································32 3. PROPERTIES OF WAVES··············································································· 36 3.1. General waves··············································································36 3.2. Sound························································································38 3.3. Light·························································································39 4. ELECTRICITY···························································································· 46 4.1. Static electricity············································································46 4.2. Electric circuit··············································································47 4.3. Practical electricity circuit································································52 5. MAGNETISM····························································································· 55 5.1. Simple phenomenon of magnetism······················································55 5.2. Electromagnetic effect ····································································57 6. INTRODUCTORY ELECTRONICS··································································· 62 6.1. Electron ·····················································································62 6.2. C.R.O.·······················································································62 7. ATOMIC PHYSICS······················································································· 64 7.1. Nuclear atom ···············································································64 7.2. Radioactivity ···············································································65 www.zedmaterials.com www.zedmaterials.com
1 1. GENERAL PHYSICS 1.1. Quantity and Unit Physical quantities There are many physical quantities in Physics. These Physical quantities can be divided into two types as shown below; Type of quantities Base quantity Derived quantity Example Mass Length Time Current Temperature Speed Volume Area Force Explanation They have only one SI unit. They can be expressed by combining suitable base quantities. SI unit The value of a physical quantity is written as a number by a suitable unit. The International System of Units is adopted in Physics. The following table shows some of SI units. Physical quantity SI unit Symbol for unit Example Length metre m 100m Mass kilogram kg 60kg Time second s 30s Current Ampere A 15A Temperature Kelvin K 150K (Basically, units of quantities are shown as SI units or derived SI units in this textbook.) Prefixes Sometime a physical quantity is too big or too small to be conveniently expressed in SI units. Then some symbols are used as the prefixes instead of Zeros or many places. Prefixes are multiples or decimals of ten. The following table shows some prefixes Prefixes Symbol Exponent Meaning Example Mega M 106 1,000,000 3Mm = 3,000,000m kilo K 103 1,000 5km = 5,000m centi C 10-2 1/100 (=0.01) 2cm = 0.02m Milli M 10-3 1/1000 (=0.001) 6mm = 0.006m Micro Μ 10-6 1/1000000 (=0.000001) 7μm = 0.000007m Scalar and Vector Definition A scalar is a quantity having magnitude only. (e.g. mass, length, area, volume, density, time, distance, speed, energy, temperature, current, voltage...) Definition A vector is a quantity having both magnitude and direction. (e.g. weight, displacement, velocity, acceleration, force, moment...) www.zedmaterials.com www.zedmaterials.com
2 1.2. Length and Time Length Definition Length is defined as the measurement of something from one end to the other. SI unit is metre. The symbol of unit is m. Instruments for measuring length Instrument Uses for length Accuracy Example of measured objects Measuring tape Long length 1mm Length of classroom, Height of building Ruler Medium length 1mm Width of paper, Length of pen Vernier calipers Short length 0.1mm Diameter of pen, Internal diameter of tube Micrometer screw gauge Very short length 0.01mm Diameter of hair, Thickness of razor blade Ruler and Measuring tape How to use the ruler or the measuring tape (1) Put the 0 mark on the end of the object. (2) Read the mark at the other end of the object. Caution to use; The eye must be placed vertically above the mark on the scale. Vernier calipers A pair of vernier calipers is shown in the diagram. The outside jaws are usually used to measure lengths of something such as external diameter. And inside jaws are used to measure internal diameter of a tube or cylinder. How to use the vernier calipers (1) Put an object to be measured between jaws. (2) Read the main scale before the 0 mark of vernier scale. (3) Look at the vernier scale and find a marking on the vernier scale that is in line with the main scale. (Commonly, the reading on the vernier scale is for the 2nd place of decimal in centimetre.) (4) Add the main scale reading and the vernier scale reading. [Example] 0 2 Object Wrong (1.2cm) Correct (1.3cm) Wrong (1.4cm) 0 mark Inside jaws Outside jaws Vernier scale Main scale Stem 1 2 0 5 Main scale reading = 1.2cm (before the 0 mark of vernier scale.) Vernier scale reading = 0.05cm Measured object (in line with the main scale) Main scale reading + vernier scale reading = 1.2 + 0.05 = 1.25 cm Step (4) Step (3) Step (2) Step (1) www.zedmaterials.com www.zedmaterials.com
3 Micrometer screw gauge A micrometer screw gauge is shown as the diagram. How to use the micrometer screw gauge (1) Thimble is turned until the object is gripped between the anvil and the spindle very gently. (2) Read the main scale on the sleeve before the edge of thimble. (3) Look at the circular scale on the thimble. Find a marking on the circular scale that is in line with the horizontal line of the main scale. (Commonly, each division of circular scale represents a length of 0.01mm) (4) Add the main scale reading and the circular scale reading. [Example] Time SI unit: second (The symbol is s) Other units: minute, hour, day, month, year, century Conversion of the unit 1year = 365days = 8760hours = 525600minutes = 31536000s 1 day = 24hours = 1440minutes = 86400s 1hour = 60minutes = 3600s 1minute = 60s Instrument for measuring the time → Clock, Watch, Stopwatch, Pendulum Simple pendulum The diagram below shows a simple pendulum with length l. The length l should be from the ceiling to the centre of the bob. Definition Period (T) is defined as the time taken for one complete oscillation. (time taken from A to C and back again to A.) T = t n T: Period [s] n: number of oscillation t: time taken for n oscillation [s] Experiment : What changes the period of pendulum? 1standard 2shorter arc 3heavier bob 4shorter string Formula frame sleeve thimble Main scale Circular scale ratchet anvil spindle Measured object 1 2 3 4 15 10 Main scale reading = 4.5 mm (before the edge of thimble.) Step (2) Circular scale reading = 0.12 mm (in line with the horizontal line of the main scale.) Step (3) Circular scale Main scale Main scale reading + circular scale reading = 4.5 + 0.12 = 4.62 mm Step (4) A C B l One complete oscillation www.zedmaterials.com www.zedmaterials.com