Physics Lect 5
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Density
 ρ = m / V
 m: mass
 V: volume
 * remember that density changes with compression because volume will change

Specific Gravity
 Makes density more intuitive
 SG = ρ_{substance} / ρ_{water}
 ρwater: 1 g/cm^{3} or 1000 kg/m^{3 }

Pressure
 P = F / A
 when 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 surface
 P = ρgy
 * remember that if the container is open you must add P_{atmos} which is 101 000 Pa

Pascal's Principal
 Pressure applied to an incompressable fluid will be evenly distributed
 a 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 volume
 an object floating displaces a volume of fluid equal to its weight

Buoyancy Force
 Submerged: F_{b} = ρ_{fluid} V g
 Floating: F_{b} = mg_{obj} = mg_{fluid}
 Fraction Submerged: ρ_{obj} / ρ_{fluid}

Center of Buoyancy
 is the point were the center of mass would be if the object were uniformly dense
 the actual center of the object

Fluids in Motion  Types of Motion
 1) Random Translational  contributes to fluid pressure as in a fluid at rest
 2) Uniform Translational  shared by molecules at a given location
 energy from these two types of motion can be converted back and forth

How do real fluids compare to ideal fluids?
 real have drag, viscocity
 drag works at the fluidobject interface, therefore the greatest velocity will be at the point farthest from that interface

Flow Rate
 Q = A v
 Q: volume flow rate
 A: area
 v: velocity

Bernoulli's Equation
 P + ρgh + 0.5ρv^{2} = K
 the sum of these three terms is a constant at any point in the fluid
 term 1: pressure
 term 2: potential
 term 3: kinetic

As velocity increases, pressure
 decreases
 think of the bee swarm standing vs. running analogy

Surface Tension
 temp dependent  the higher the temp the weaker the surface tension
 if 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