Physics 1010Comprehensive ReviewPart-1Extra Credit Grades Will be posted on website by Tuesday for thecurrent EC assignment EC credits for the surveys will be postedafter all surveys have been completed,probably next Thursday Last EC assignment will post tonight, duenext ThursdayGeneral Test Information Final is worth 80 points, as much as all yourmid-terms put together Equivalent to ~16% of your final grade;that’s more than a letter grade Will do comprehensive reviews from now on Most review questions will be graded forclicker credit, BUT last week of reviews willNOT be gradedGeneral Test Information All material is eligible for the final That includes Extra Credit Assignments (eg.aeropllanes, greenhouse effect, friction) Bring questions to classSkill and Concept Overview Concepts – velocity, acceleration, force, Newton’slaws, gravity, springs;work, momentum, energy, power, conservation laws;pressure;oscillators, waves (sound and EM);black bady radiation, temperature scales;electric charge, magnetic dipoles, Coulomb force;voltage, current, resitance, circuits Skills – read and interpret graphs, linear equations,quadratic equations (squares or square roots).Velocity Velocity is the changeof an object’s positionwith respect to time. x is position, v isvelocity.txv!!=Velocity is the slope!Acceleration Acceleration is the change of anobject’s velocity with respect totime. v is velocity, a is acceleration.tva!!=Acceleration is the slope!Kinematic Equations of Motion Rearranging equation from previous slide:Similarly for position:v = vi + atx = xi + vit + (1/2) at2Newton’s First Law An object that is not subject to any outsideforces moves at a constant velocity. When an object is not accelerating, it can stillbe subject to external forces, but the net forceis zero.Newton’s Second Law Fundamental equation of dynamics:F = m a Acceleration is in the same direction as netforce.Newton’s Third Law For every force that one objects exerts on asecond object, there is an equal and oppositeforce that the second object exerts on the first. This does not apply to two forces acting onthe same object.Gravity Objects of different masses fall at the samerate. The gravitational force on an object must beproportional to its mass.2/ 8.9 smgmgFgravity!=Friction Frictional forces oppose motion. Two types: static and sliding. Sliding friction force is generally smaller thannormal force. Friction force is related to the force that isnormal to the contact surface.Springs Hooke’s law:kxFspring!= The spring force is a restoring forceproportional to the displacement of theobject. Spring constant k depends on the type ofspring.Momentum & Impluse Momentum is a body-specific quantity that is conservedduring collisions. Its unit is kg m/s. Impulse is the change in an object’s momentum over sometime interval, and is equal to the force applied to the objecttimes the duration of that force. Its unit is kg m/s = N smvp !ptFI !=!"Work Work is defined as the displacement of an objectmultiplied by the force on that object in thedirection of the displacement. Its unit is N m = J. Net work is the net force on the object in thedirection of the displacement multiplied by thedisplacement.xFW !"Power Power is the work done per unit time. Itsunit is J/s = W.tW!"#Pressure and Density Pressure is defined as the force applied to a surfacedivided by the area of that surface. Its unit is N/m2= Pa. Mass density is defined as the mass of an objectdivided by the volume of the object. Its unit iskg/m3.AFP =Vm=!Energy Energy comes in a variety of forms: kinetic,thermal, spring potential, gravitational potential,etc. Energy always has the unit J. The forms we discussed in class:221mvEk=mghEg=221kxEsp=Conservation of Momentum As previously mentioned, momentum isconserved during collisions. This is not themomentum of the individual objects – onlythe total momentum of the system isconserved.ffiivmvmvmvm2121+=+Conservation of Energy The total mechanical energy of a system isconstant in time. This allows us to compare the energyquantities at different times.K++++=thspgkEEEEEffiimghmvmghmvE +=+=222121The Work-Energy Relation If net work is done on an object, energy istransferred to that object. That energy isequal to the work done (notice the same unitsfor each). The energy can be in any form whatsoever.EWnet!=The energy change can be kinetic,potential, spring, or thermal.Bouyancy ForcesArchimedes’ Principle:The buoyancy force on an object is equal to the weight of the fluid displaced by the object.Fb = Wf = ρ V gWhere ρ is the density of the displaced fluidOscillators A harmonic oscillator is something thatexhibits periodic motion where the period isindependent of the amplitude of the motion.kmTsp!2=glTpendulum!2= The frequency of an oscillator is the inverseof the period.Tf1=Sound waves Sound waves are compression (longitudinal) wavesthat travel through the air (or water, or other fluids orsolids). The pitch of a sound is directly related to itsfrequency. The speed, frequency, and wavelength of a soundwave exhibit a simple relationship:!fvs=Useful Formulae Kinematics: v=v0+at, x=x0+v0t+(1/2)at2 Newton’s II: F = ma Gravity: Fw= mg (g=9.8 m/s2) Friction: Ff = µFN (µ ~0.3 if not otherwisegiven) Hook’s Law: Fs= -kx Momentum: p = mvUseful Formulae Work: W=F L (L is length along which F isapplied) Torque: T=F d (d is perpendicular distanceto the line of force) Rotational Newton’s II: T=Iα (I=moment of inertia, α=angualacceleration)Useful Formulae Power: P=E/t Pressure: P=F/A (careful, confusing notation) Density: ρ=m/V Bernoulli: P+ρgh+(1/2)ρv2=const. Energy: Ek=(1/2)mv2, Eg=mgh, Es=(1/2)kx2 Buoyancy: Fb = Ffluid weight = ρfluidVfluidgUseful Formulae Spring oscillator: Pendulum: Period-Frequency: f=1/T Waves: v= λ /T=λfkmTsp!2=glTpendulum!2=Useful Formulae Black Body Radiation: P=σT4 Coulomb Force: F = k (q1 q2)/R2 Ohm’s Law: V=IR EPE = qV Circuits: P=IV; parallel: same voltage,currents add upseries: same current, voltages add upUseful Formulae Transformers: Right hand rule:currentNorth poleUnit Conversions k (kilo) = 1000 (1km=1000m) M (mega) = 1,000,000 (1MW=1,000,000W) c (centi) = 1/100 (1m=100cm) m (milli) = 1/1000 (1m=1000mm) µ (mirco)
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