Introduction to physics for studentsPresentation Transcript
Understanding Physics1. Like all sciences, physics is based onexperimental observations andquantitative measurements.
Understanding Physics2. Historically, until nineteenthcentury, physics was called naturalphilosophy.
Understanding Physics3. Physics is a branch of scienceconcerning study of naturalphenomena, that is, properties ofmatter and energy.
Understanding Physics• 4. Some examples of naturalphenomena are(a) sunrise and sunset,(b) lightning and thunder,(c) rainbow and blue sky,(d) earthquake and tsunami.
Field of study in PhysicsIn general, physics is concerned withthe study of energy and the propertiesand structure of matter.
Field of study in PhysicsPhysicsClassical Modern
Field of study in Physics• deals with questions regarding motion and energyMechanics (forces and motion)HeatSoundEelectricity and magnetismLightPhysicsClassical Modern
Field of study in Physics• concentrates on scientific beliefs about the basic structure ofthe material worldPhysicsClassical Modern
Understanding Base Quantities andDerived Quantities
Base Quantities• 1. Physical quantities are quantities thatcan be measured.
Base Quantities2. A physical quantity can berepresented by a symbol of thequantity, a numerical value for themagnitude of the quantity and the unitof measurement of the quantity. Length, l = 1.67 ml - symbol 1.67is the value m - unit
Base Quantities• 3. Base quantities are physical quantities thatcannot be defined in terms of other quantities.Base quantity :LengthDerived quantity :Area = length x length
Base QuantitiesBase quantities SI base unitsName Symbol Name SymbolLength l Metre mMass m Kilogram KgTime t Second sElectriccurrentI Ampere ATemperature T Kelvin K
Derived Quantities 1 Derived quantities are physicalquantities derived from base quantities bymultiplication or division or both. The unitfor a derived quantity is known as aderived unit.
Derived QuantitiestakenTimentDisplacemetakenTimevelocityinChangesms -1volumeMasskgm3Derived quantities Derived unitsArea = Length x breadth [Area] = m x m = m2Velocity = [Velocity] = = ms–1Acceleration=Density = [Density] = = kgm–3ms[Acceleration] == ms–2
Vectors and Scalars
ScalarA SCALAR is ANY quantity inphysics that hasMAGNITUDE, but NOT adirection associated withit.Magnitude – A numericalvalue with units.ScalarExampleMagnitudeSpeed 20 m/sDistance 10 mAge 15 yearsHeat 1000caloriesTemperature 37OCMass 100kgVolume 5m3
VectorA VECTOR is ANY quantity inphysics that has BOTHMAGNITUDE andDIRECTION.Vector Magnitude& DirectionVelocity 20 m/s, NAcceleration 10 m/s/s, EWeight 100N(towardcenter of theearth)Force 5 N, WestFav,,Vectors are typically illustrated bydrawing an ARROW above thesymbol. The arrow is used toconvey direction and magnitude.