Physics #4 Flashcards
the ratio of mass to volume is ____
density
1 cubic cm = ____ mL
1
1 cubic m = ______ L
1000
what is the density of water
1 g/cm^3 OR 1000 kg/m^3
1 Pascal = ____
1 N/m^2
is pressure a vector or a scalar?
it is a scalar because it is equal throughout the container of the fluid.
at higher altitude is there more or less atmospheric pressure?
less
what is a synonym for absolute pressure?
hydrostatic pressure
what is absolute pressure?
the total pressure that is exerted on an object that is submerged in a fluid.
____ is the study of fluids at rest and the forces and pressures associated with standing fluids
hydrostatics
how does a body of water react to high pressure or low pressure system above it
high pressure system: valley in body of water
low pressure: mountain in body of water
Pascal’s principle of hydrostatics, or Pascal’s law, states that ____
the pressure exerted anywhere in a confined incompressible liquid is equally transmitted throughout the fluid.
In Pascal’s principle, the larger the area the _____ the force over the _____ distance
larger
smaller
Archimede’s principle
a body wholly or partially immersed in a fluid will be buoyed upwards by a force equal to the weight of the fluid that it displaces
An object will only be as submerged in water to the point where the volume of displaced water produces a force _______ to the weight of the object
equal
_____ causes the liquid to form a thin but strong layer like a skin at the liquids surface
surface tension
cohesion
the attractive force that a molecule of a liquid feels toward other molecules of the same liquid
adhesion
the attractive force that a molecule of liquid feels toward the molecules of some other substance.
when does a concave vs. convex meniscus form?
a concave meniscus forms when adhesion>cohesion
what do you know from the following information: a block is fully submerged 3 inches below the surface of a fluid, but is not experiencing any acceleration?
- the densities of the two substances are equal
- the volume of the block and the displaced fluid are the same
- the buoyant force equals the weight of the block and is equal to the weight of the displaced fluid
the resistance of a fluid to flow is ____
viscosity
increased viscosity increases ____
viscous drag
nonconservative force
more viscous fluids ____ more energy while flowing
lose
SI unit for viscosity
(Pa)(s)
laminar flow
smooth and orderly
the layer of fluid closer to the wall of a pipe flows ____ than more interior layers of fluid
more slowly
turbulent flow
rough and disorderly
in unobstructed fluid flow, turbulence can arise when the speed of the fluid exceeds a certain _____
critical speed
when critical speed is exceeded, where does laminar flow occur?
close to wall, called the boundary layer
boundary layer
when critical speed is exceeded, it is where laminar flow occurs
____ is constant for a closed system and independent of changes in cross-sectional area
flow rate
what does the continuity equation tell us?
that fluids will flow more quickly through narrow passages and more slowly through wider ones.
energy density
similar to pressure: energy per cubic meter
pitot tube
specialized measurement devices that determine the speed of fluid flow by determining the difference between the static and dynamic pressure of the fluid at given points along the tube
measures static pressure during flow to calculate speed
explain the venturi effect
fluid flows faster through smaller radius, the pgh term remains constant because it averages out, so therefore the static pressure at the faster moving location is less.
what makes the circulatory system challenging for flow?
- nonconstant flow rate: gravity, valves, elasticity of our vessels
- loss of volume into lymphatic ducts
as blood flows away from the heart, each vessel has a _____ resistance, except when you reach the ______. because _____
higher
capillaries
resistors in parallel
compare the volume of blood in venous and arterial circulation
more blood in veinous circulation
can the continuity equation be applied to human circulation?
no, nonconstant flow rate
how does total resistance change when air is breathed in
decreases because there are more pathways in parallel
decreasing speed of fluid will ____ its pressure
increase
what is the density from in the gauge pressure equation?
density of the fluid!
does blood flow faster through the aorta or capillaries?
aorta because of the summation of the cross sectional area of the capillaries.
