Things You Should Know About Regents Physics

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Egbert Washington
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Measuement and Mathematics Estimation: 1 kg 2.2 lbs 1 apple 1 N 1 quate 5 g 0.

1 Measuement and Mathematics Estimation: 1 kg 2.2 lbs 1 apple 1 N 1 quate 5 g kg Ode of magnitude: powe of ten (thickness of pape 10-4 m) Fundamental units Quantity Units Symbol Length mete m Mass kilogam kg Time second s Electic cuent ampee A Geneal Relationships: Constant y c Diect y mx Slope Δy/Δx Linea y mx + b Linea (Indiect) y -mx + b Invese y c/x Invese-Squae (Quadatic) y c/x 2 Diect-Squae (Quadatic) y cx 2 Scalas (magnitude only) Vectos (magnitude and diection) only 9! Distance Displacement Speed Velocity Acceleation Foce (weight, nomal foce, etc.) Anything else! Momentum Impulse Fields (gavitational, electic, magnetic) sinθ cosθ opp hyp adj hyp opp tanθ adj d Gaphs of Motion v Constant Velocity Two Types of Motion Constant Acceleation Slope velocity t Slope acceleation Aea displacement t Foces ae balanced Foces ae unbalanced Fnet 0, a 0 Fnet 0, a 0 In equilibium not in equilibium Newton s fist law Newton s second law Distance v. Speed v. Acceleation v. Distance v. Speed v. Acceleation v. time time time time time time Hoizontal Launch x Y d h t the same a vi vi 0 vf vavg vi vi Pojectiles Hoizontal constant speed Angle Launch Vetical constant acceleation x Y d t whole half a vi Vx Vy vf Vx 0 (top) vavg Vx

2 Mechanics Vectos Equilibium: no net foce, no acceleation, constant velocity o at est, foces fom a closed figue Concuent vectos: placed tail-to-tail Component vectos: must be head-to-tail to find esultant Resultant foce F net : head-to-head and tail-to-tail with components Range of possible esultants: Maximum sum of vectos Equilibant: equal and opposite to esultant Minimum diffeence of vectos Box on a Hill in Equilibium: mgsinθ F f o F A o F T and mgcosθ F N Mass (m): inetia, amount of matte, constant fom place to place, units: kg Weight (F g ): foce of gavity, changes fom place to place, units: N Fomula: F g mg Concuent Resultant Maximum Θ 0 0 Minimum Θ Equilibant Tiangle ule sum of any 2 sides thid side fo foces to be in equilibium FA FF FT F G Inclined Plane FN F m g cosθ F m g sinθ Two names fo little g : 1) acceleation due to gavity, units: m/s 2, fomula: g GM/ 2 2) gavitational field stength, units: N/kg, fomula: g F g /m Fiction Static fiction (at est) applied foce until motion stats Cicula Motion F c, a c Kinetic fiction (in motion) is constant Maximum static fiction is geate than kinetic fiction F f μf N Newton s Thid Law: Wheneve A exets foce on B, B exets equal/opposite foce on A. (Action/eaction pais: bat and ball, Eath and Moon, hamme and nail) v d cicumfeence 2π v t peiod T v mv ac Fc mac 2 2 Foces ae the same but the effects of the foces ae not: ma ma Newton s Law of Univesal Gavitation F g Gm m Consevation Laws: electic chage, momentum, mass and enegy

Enegy Wok: foce and displacement must be paallel W Fd Mechanical Enegy: PE g + PE s + KE Total Enegy: PE g + PE s + KE + Q Intenal Enegy Q: themal enegy, heat due to fiction/ai esistance Collisions

3 Enegy Wok: foce and displacement must be paallel W Fd Mechanical Enegy: PE g + PE s + KE Total Enegy: PE g + PE s + KE + Q Intenal Enegy Q: themal enegy, heat due to fiction/ai esistance Collisions Consevation of Momentum: pbefoe pafte Isolated System: no extenal foces Elastic Collision: total KE is conseved Sticky (inelastic) m1v1 + m2v2 (m1 + m2) vf Powe: ate of change of enegy, ate of dong wok (units: Watts (W) J/s) PE g inceases if height inceases. KE inceases if speed inceases. PE s inceases if sping is stetched o compessed. Bouncy m1v1 + m2v2 m1v1 + m2v2 (elastic) Remembe Moving to the left gets a NEGATIVE sign! Fomulas fo spings: PE s ½ kx 2 k sping constant (units: N/m) F s kx Consevation of Enegy: E T E T PE g + PE s + KE + Q PE g + PE s + KE + Q Wok-Enegy Theoem: W ΔE T Electicity Conductos (metals) have fee electons, insulatos do not. Explosion Objects become chaged by losing o gaining electons (not potons). Elementay Chage: poton o electon 1 Coulomb of chage 6.25 x elementay chages Chage of Electon: q -1e OR q x C Mass of Electon: m 9.11 x kg Chage of Poton: q +1e OR q x C Mass of Poton: m 1.67 x kg Equal and opposite foces, impulses, changes in momentum, and contact times Diffeent speed based on mass mama mvmv Coulomb s Law (electic foce, electostatic foce) Electic Field (units: N/C o V/m) F e kq q E F e Lines go fom + to -. Lines neve coss. Lines show diection of foce on small positive test chage. Field is most intense whee field lines ae most dense. q If two o moe identical chaged sphees touch, the final chage on each is the aveage chage (total chage # of sphees). The total chage is conseved. A neutal object will be attacted (neve epelled) by any chaged object. If two objects attact, they could have opposite chages o one could be neutal. If two objects epel, they must have the same type of chage. Chaging by conduction: diect contact - electoscope gets same chage as od Chaging by induction: no diect contact - electoscope gets chage opposite of od

Electic potential diffeence (voltage): wok done pe unit chage (V W/q) Resistance of a wie: R ρl/a whee A π 2 Least esistance (best conducto): shot, fat, cold Most esistance (wost conducto): long,

4 Electic potential diffeence (voltage): wok done pe unit chage (V W/q) Resistance of a wie: R ρl/a whee A π 2 Least esistance (best conducto): shot, fat, cold Most esistance (wost conducto): long, skinny, hot Voltmete: connect in paallel, infinite intenal esistance Ammete: connect in seies, zeo intenal esistance Seies Cicuit R e q T R + R + R V V + V + V Contol: cuent stays the same Resistance adds up (geate than geatest) Adding exta esisto inceases total esistance and deceases total cuent. Resistance: R V/I Paallel Cicuit IT I1+ I2 + I R R R R eq Contol: voltage stays the same Resistance adds down (less than least) Adding exta esisto deceases total esistance and inceases total cuent. Potential diffeence V Volt V J/C Cuent I Amps A C/s Resistance R Ohms Ω V/A Powe P Watts W J/s Chage q Coulombs C Enegy W Joules J N m Mechanical Powe: P W/t Fd/t Fv Electical Powe: P VI I 2 R V 2 /R Ohmic Device: follows Ohm s law (Vα I at constant T) constant esistance Non-Ohmic Device: esistance not constant (eg. filament lamp) Slope 1/R Slope R 1 electonvolt (ev) 1.60 x J 1 kilowatt hou (1000 W)(1 h) 3.6 x 10 6 J Thee units of enegy: joules, electonvolts, kilowatt hous Magnetic Fields Fom N to S, density stength (intensity) Diection of lines diection of compass needle Two Pinciples of Electomagnetism: 1) An electic cuent (o moving chaged paticle) geneates a magnetic field. 2) A changing/moving magnetic field induces an electic cuent (electomagnetic induction).

Waves Mechanical: needs medium Electomagnetic: no medium Tansvese: pependicula Things You Should Know About Regents Physics Longitudinal: paallel Radio Wave: electomagnetic wave speed 3.

Enegy α amplitude Speeds up when going fom ai to wate Can t be polaized Light Tansvese, electomagnetic Speed c 3.

5 Waves Mechanical: needs medium Electomagnetic: no medium Tansvese: pependicula Things You Should Know About Regents Physics Longitudinal: paallel Radio Wave: electomagnetic wave speed 3.00 x 10 8 m/s Peiod (T): seconds/cycle Fequency (f): cycles/second Wave equation: v fλ Sound Longitudinal, mechanical Speed 331 m/s (STP) 340 m/s (oom temp) Amplitude loudness (volume) Fequency pitch Enegy α amplitude Speeds up when going fom ai to wate Can t be polaized Light Tansvese, electomagnetic Speed c 3.00 x 10 8 m/s (vacuum) Amplitude α bightness (intensity) Fequency α enegy (E hf) Slows down when going fom ai to wate Can be polaized Red: long wavelength, low fequency Blue: shot wavelength, high fequency In Phase: A, E, I Out of Phase by o λ/2: A, C In one medium : f α 1/λ Contol: speed - you can only change the speed of the wave by changing the popeties of the medium) Law of Reflection: θ i θ Cossing a bounday: v α λ Contol: fequency stays the same, so does peiod and phase Had eflection: out of phase Soft eflection: in phase Constuctive intefeence: in phase θi θ Refaction: changing diection when changing speed when cossing a bounday FAST: into fast, bend away fom nomal (high n to low n) into slow, bend towads nomal (low n to high n) Diffaction: bending aound obstacle o speading though opening Noticeable diffaction: when size of opening appox. equal to size of wavelength as opening gets smalle, moe diffaction effects Destuctive intefeence: out of phase Dopple Effect: appaent change in fequency due to elative motion Constant low fequency, Deceasing amplitude Dopple Shift fo Light: blue shift object moving towads ed shift object moving away Constant high fequency, Inceasing amplitude Standing Wave: Two identical waves taveling in opposite diections in the same medium intefee Light slows down, bends towads the nomal, and has a shote wavelength when it entes a medium with a highe index. The fequency stays the same. Resonance: enegy is tansfeed to a system by making it vibate at its natual fequency esulting in lage amplitude standing waves Examples: guita stings, bidges, swings, wine glasses Ode of Electomagnetic Spectum: Souce acceleating chaged paticles Radioactive Monkeys In Viginia Use X-ay Guns lowest to highest fequency and enegy Fundamental Wave: lowest fequency (f 1 ), λ m Visible Light: 400 nm (violet) 700 nm (ed)

Double Slit Diffaction and Intefeence: equally spaced bight and dak bands Red Spead Single Slit Diffaction: wide and bight cental maximum Dispesion: speading out of light

Angle (θ C ): incident angle fo which the efacted angle is 90 0 Fomula: sin θ C n 2 /n 1 Total Intenal Reflection: all light is eflected at suface, none is efacted only

6 Double Slit Diffaction and Intefeence: equally spaced bight and dak bands Red Spead Single Slit Diffaction: wide and bight cental maximum Dispesion: speading out of light into components due to efaction each colo has slightly diffeent index and speed Blue Bends Best - slowest Red Resists Refaction - fastest Total Intenal Reflection Citical Angle (θ C ): incident angle fo which the efacted angle is 90 0 Fomula: sin θ C n 2 /n 1 Total Intenal Reflection: all light is eflected at suface, none is efacted only occus when light tavels fom high to low index and incident angle is geate than θ C Majo use: fibe optic cables Polaization Only tansvese waves can be polaized light yes, sound no. Polaized Light: vibates in only one diection Natual Polaization: light is patially polaized when it eflects off a suface 50% of unpolaized light tansmits though a single polaize. Paallel polaizes: 50% passes though both Moden Physics Pependicula polaizes: 0% passes though second Slope Planck s constant (h) E mc 2 (only use if E is in Joules and m is in kg) 1 u 9.31 x 10 2 MeV (E photon E i - E f ) Hadons made of quaks, leptons don t beak down futhe Antimatte same mass, opposite chage Alpha paticle helium nucleus (2 potons and 2 neutons) Positon anti-electon positive electon Poton uud Neuton udd Fundamental foces: EM and gavity long-ange; Stong and weak shot-ange

Things You Should Know About Physics

Things You Should Know About Physics Measuement and Mathematics HONORS Fundamental units Quantity Units Symbol Estimation: 1 kg 2.2 lbs 1 apple 1 N 1 quate 5 g 0.005 kg Ode of magnitude: powe of ten (thickness of pape 10-4 m) Length mete