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PHY093 PHY093 Physics 1Physics 1IntroductionIntroduction

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Physics (Giancoli)Physics (Giancoli)

The most basic of the sciencesThe most basic of the sciences Deals with behavior and structure of matterDeals with behavior and structure of matter Usually divided intoUsually divided into (a) (a) classical physicsclassical physics: : motion, fluids, heat, motion, fluids, heat,

sound, light, electricity and magnetismsound, light, electricity and magnetism (b) (b) modern physicsmodern physics: : relativity, atomic structure, relativity, atomic structure,

condensed matter, nuclear physics, elementary condensed matter, nuclear physics, elementary particles and astrophysicsparticles and astrophysics

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Why study physics? Why study physics? (Giambatista et al.)(Giambatista et al.)

Since physics describes matter and its Since physics describes matter and its basic interactions, all natural sciences basic interactions, all natural sciences are build on a foundation of the laws of are build on a foundation of the laws of physics.physics.

In today’s technological world, many In today’s technological world, many important devices can be understood important devices can be understood correctly with the knowledge of the correctly with the knowledge of the underlying physics.underlying physics.

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Light interference produces Light interference produces shimmering blue color of a shimmering blue color of a butterfly butterfly

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CAT scanCAT scan

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How a CD is read.How a CD is read.

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Fiber optics carry signals Fiber optics carry signals efficiently based on the efficiently based on the principle of total internal principle of total internal reflection reflection

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Why study physics?Why study physics?

By studying physics, you acquire skills that are By studying physics, you acquire skills that are useful in other disciplines.useful in other disciplines.

Society’s resources are limited, so it is Society’s resources are limited, so it is important to use them in beneficial ways and important to use them in beneficial ways and not squander them on scientifically impossible not squander them on scientifically impossible projects.projects.

By studying physics, we hope that you develop By studying physics, we hope that you develop a sense of beauty of the fundamental laws a sense of beauty of the fundamental laws governing the universe.governing the universe.

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The nature of physicsThe nature of physics(Cutnell & Johnson)(Cutnell & Johnson)

The science of physics has developed The science of physics has developed out of the out of the efforts of men and womenefforts of men and women to to explain our physical environment.explain our physical environment.

The exciting feature of physics is its The exciting feature of physics is its capacity for capacity for predicting how nature will predicting how nature will behavebehave in one situation on the basis of in one situation on the basis of experimental data obtained in another experimental data obtained in another situation. Such predictions place physics situation. Such predictions place physics at the at the heart of modern technologyheart of modern technology..

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Length or distances studied Length or distances studied in physics (order of in physics (order of magnitude)magnitude)

Radius of proton or neutron Radius of proton or neutron 1010-15-15 m m Atom Atom 1010-10-10 m m Virus Virus 1010-7-7 m m Height of Mount Everest Height of Mount Everest 101044 m m Earth diameter Earth diameter 101077 m m Sun diameter Sun diameter 101099 m m Distance earth to sun Distance earth to sun 10101111 m m Farthest galaxy visible Farthest galaxy visible 10102626 m m

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Some masses (approx.)Some masses (approx.) ElectronElectron 1010-31-31 kg kg Proton / neutronProton / neutron 1010-27-27 kg kg DNA moleculeDNA molecule 1010-17-17 kg kg MosquitoMosquito 1010-5-5 kg kg PersonPerson 101022 kg kg ShipShip 101088 kg kg EarthEarth 6 x 106 x 1024 24 kgkg SunSun 2 x 102 x 103030 kg kg GalaxyGalaxy 10104141 kg kg

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Some time intervals Some time intervals (approx.)(approx.)

Lifetime of very unstable sub-atomic Lifetime of very unstable sub-atomic particleparticle

1010-23-23 s s

Lifetime of muonLifetime of muon 1010-6-6 s s

Time between human heartbeatsTime between human heartbeats 101000 s (1s) s (1s)

One yearOne year 3 x 103 x 107 7 ss

Human lifespanHuman lifespan 2 x 102 x 109 9 ss

Life of earthLife of earth 10101717 s s

Age of universeAge of universe 101018 18 ss