# Physics Lect 5

 The flashcards below were created by user laskiru on FreezingBlue Flashcards. Density ρ = m / Vm: massV: volume* remember that density changes with compression because volume will change Specific Gravity Makes density more intuitiveSG = ρsubstance / ρwaterρwater: 1 g/cm3 or 1000 kg/m3 Pressure P = F / Awhen an object is submerged: pressure is equal to the force felt on the object divided by the surface area* remember that pressure is there regardless of if the object is, this just makes it more intuitive Fluids at Rest Fluids are at rest when they are only experiencing a force perpendicular to its surfaceP = ρgy* remember that if the container is open you must add Patmos which is 101 000 Pa Pascal's Principal Pressure applied to an incompressable fluid will be evenly distributeda hydrolic lift utilizes this principal (F applied to smaller S.A. --> P trans --> since the larger S.A. is larger the F is greater on it (no change in work though so the distance is less) Archimedes Principal an object submerged in water displaces a volume of fluid equal to its own volumean object floating displaces a volume of fluid equal to its weight Buoyancy Force Submerged: Fb = ρfluid V gFloating: Fb = mgobj = mgfluidFraction Submerged: ρobj / ρfluid Center of Buoyancy is the point were the center of mass would be if the object were uniformly densethe actual center of the object Fluids in Motion - Types of Motion 1) Random Translational - contributes to fluid pressure as in a fluid at rest2) Uniform Translational - shared by molecules at a given locationenergy from these two types of motion can be converted back and forth How do real fluids compare to ideal fluids? real have drag, viscocitydrag works at the fluid-object interface, therefore the greatest velocity will be at the point farthest from that interface Flow Rate Q = A vQ: volume flow rateA: areav: velocity Bernoulli's Equation P + ρgh + 0.5ρv2 = Kthe sum of these three terms is a constant at any point in the fluidterm 1: pressureterm 2: potentialterm 3: kinetic As velocity increases, pressure decreasesthink of the bee swarm standing vs. running analogy Surface Tension temp dependent - the higher the temp the weaker the surface tensionif the adhesive forces (to the container) are stronger than the cohesive forces (between molecules) the miniscus will be a 'U' shape Solids and Heat Typically expand when heated Authorlaskiru ID58894 Card SetPhysics Lect 5 DescriptionFluids and Solids Updated2011-01-10T03:21:24Z Show Answers