# Home End HolisticTuition CashPlants Chapter 1: Introduction to Physics Form 4 1 Physics Next > The study of matter.

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Home End HolisticTuition CashPlants Chapter 1: Introduction to Physics Form 4 1 Physics Next > The study of matter

Home End HolisticTuition CashPlants Objectives: (what you will learn) Objectives: (what you will learn) 1)understand Physics 2)base quantities & derived quantities 3)scalar quantities & vector quantities 4)measurements, using instruments 5)processes in scientific investigations Physics: Chapter 1 2 < Back Next >

Home End HolisticTuition CashPlants Understanding Physics: Physics 3 1.“Physics” derives from Latin, “physica” - the science of natural things; until 19 th century, it was called “natural philosophy”. Through its subfield of astronomy, it may be the oldest academic discipline. < Back Next > 2.Physics is a branch of Science for study of natural phenomena, which involves force, matter & energy; based on experimental observations & quantitative measurements. natural phenomenanatural phenomena

Home End HolisticTuition CashPlants Base Quantities Physical Quantities 4 Quantities that cannot be defined in any other physical quantity. < Back Next > Base QuantitySymbolSI UnitSymbol Length l meterm Mass m kilogramkg Time t seconds Temperature T KelvinK Current I AmpereA

Home End HolisticTuition CashPlants 5 < Back Next > Physical Quantities Derived Quantities Quantities derived from base quantities (through mathematical combinations). Volume = Length x Breath x Height = m 3 Density = Mass ÷ Volume = kg m -3 Velocity = Displacement ÷ Time = m s -1 Acceleration = Velocity ÷ Time = m s -2 Force = Mass x Acceleration = kg m s -2

Home End HolisticTuition CashPlants 6 < Back Next > Physical Quantities Scalar Quantity Physical quantity which has magnitude only, such as distance and mass. (Compare them to base quantities.) Vector Quantity Physical quantity which has both magnitude and direction, such as force and pressure. (Compare them to derived quantities.)

Home End HolisticTuition CashPlants 7 < Back Next > Physical Quantities Prefixes Simplifies description of physical quantities that are either very big or very small without losing data. prefixsymbolvalue picop10 -12 nanan10 -9 microµ10 -6 millim10 -3 centic10 -2 prefixsymbolvalue kilok10 3 megaM10 6 gigaG10 9 teraT10 12 1 Small quantities Big quantities

Home End HolisticTuition CashPlants 8 < Back Next > Physical Quantities Scientific Notation The standard form for numerical magnitude. Q x 10 n where 1 ≤ Q < 10 and n is an integer Examples: 0.000000696 m = 6.96 x 10 -7 m 911 000 000 kg = 9.11 x 10 8 kg

Home End HolisticTuition CashPlants 9 < Back Next >Measurements Accuracy measures how close a hit is to the target. If it is too far from the target, it is not accurate. Consistency measures how close together a group of hits is to the average value. If they are far apart from each other, they are not consistent. We want results that are both accurate & consistent. Consistent, less accurate Accurate, less consistent Not accurate, not consistent Accurate & consistent

Home End HolisticTuition CashPlants 10 < Back Next > Measuring Instruments Sensitivity = how small a change in reading that can be measured by an instrument Ruler Low, 1 mm Vernier caliper Vernier caliper Medium, 0.1 mm Micrometer screw gauge Micrometer screw gauge High, 0.01 mm

Home End HolisticTuition CashPlants 11 < Back Next > Measurement Errors Incorrect calibration of instrumentsIncorrect calibration of instruments Systematic Error Occurs in one direction only. Zero error – pointer of instrument does not return to zero when not in use, such as a ruler worn out at one endZero error – pointer of instrument does not return to zero when not in use, such as a ruler worn out at one end Repeated error in reaction timeRepeated error in reaction time Wrong assumptionWrong assumption too low too high Always negative Always positive May arise from various causes. or

Home End HolisticTuition CashPlants 12 < Back Next > Measurement Errors Random Error Size of error not constant & unpredictable. The reading is sometimes positive & sometimes negative from actual value. May arise from various causes. Parallax error – due to incorrect positioning of the eye when taking measurementParallax error – due to incorrect positioning of the eye when taking measurement Changes in the surroundings; i.e. temperature, air circulation, lighting, magnetic field, etc.Changes in the surroundings; i.e. temperature, air circulation, lighting, magnetic field, etc. Can be reduced in several ways. Repeated measurements – taking mean valueRepeated measurements – taking mean value Using mirror beneath pointer of instrumentUsing mirror beneath pointer of instrument

Home End HolisticTuition CashPlants 13 < Back Next > Scientific Investigation The processes involved Making use of all human senses Initial explanation or conclusion Making smart guesses Testing in controlled situation Documentation of results in report Start End Observation Inference Hypothesis Experiment Conclusion

Home End HolisticTuition CashPlants 14 < Back Next > Scientific Experiment Steps involved in carrying out Experiment Aim Variables Apparatus Procedures Tabulation Analysis Suggest suitable questions Manipulated, responding, & fixed List apparatus/materials, arrangement Carry out experiment in proper order Documenting data obtained Analyze data through graphs, etc.

Home End HolisticTuition CashPlants 15 Summary < Back What you have learned: 1.Understanding Physics 2.Physical Quantities Thank You 3.Measurements & Instruments 4.Scientific Investigations & Experiments

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