Term
| why are the molecular bonds of a fluid constantly breaking and reforming |
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Definition
| this is due to the high kinetic energy of the molecule |
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Term
| the only permanent force a resting fluid can exert is one |
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Definition
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Term
| in gas, why does gravity have an insignificant effect on the path of an individual molecule |
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Definition
| because of the molecules high average velocity |
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Term
| typically in fluid mechanics, we don't know how much fluid we're dealing with, so we use intrinsic properties like |
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Definition
| denisty and pressure-analogous to mass and energy |
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Term
| what is density (in terms and in equation form) |
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Definition
the heaviness of a fluid in a specified volume
density=m/V |
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Term
| for MCAT purposes, how should you think about liquid and solids in terms of denisty |
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Definition
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Term
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Definition
| this was created to compare the density of a substance with the density of water |
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Term
| there are two forms for the density of water that you should memorize, what are they |
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Definition
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Term
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Definition
| the average magnitudes of the change in momentum of these collisions divided by the time duration of the collisions and the area over which these collisions occur |
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Term
| even when there is not an object submerged into liquid, there is a constant pressure |
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Definition
| think of this as a measure of the kinetic energy of the random velocities of molecules within a fluid |
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Term
| what is the eqaution for pressure (pascals) |
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Definition
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Term
| how can you determine the pressure of a fluid |
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Definition
| P= (density)(gravity)(depth) |
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Term
| how does pasacal's principle apply to liquids but not gases |
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Definition
pressure applied anywhere to an enclosed imcompressible fluid will be distributed undiminished throughout the fluid.
it does not apply to gas because it is compressible |
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Term
| what are the two types of motion that molecules of a moving fluid can have |
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Definition
| random and uniform translational motion |
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Term
| what type of motion attributes to pressure |
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Definition
| random translational motion |
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Term
| idea fluid differs from real fluid in four ways, what are they |
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Definition
zero viscosity- meaning that there is no drag, so no opposition to motion
incompressible
lacks turbulence
they experience irrotational flow
All fluids on the MCAT are ideal-remember this |
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Term
| what is Bernoulli's equation |
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Definition
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Term
context: a tank of water has a small spigot
as the velocity of the fluid leaving increases, what happens to pressure |
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Definition
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Term
| where is the greatest velocity of a liquid |
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Definition
| the middle of the pipe, furthest distance from fluid-object interface |
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Term
| if the pipe is narrowed, how will this effect viscosity |
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Definition
| it will increase viscosity |
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Term
| in order to discuss the elasticity of a solid we must first understand two concepts, what are they |
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Definition
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Term
| what is stress and what is its equation |
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Definition
stress is the force applied to an object divided by the area over which the force is applied
the equation is: F/A and its in N/m2 |
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Term
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Definition
strain is a ratio of change in dimension compared to the original dimension
change of dimension/original dimension |
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Term
| what is modulus of elasticity |
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Definition
this is a ratio that makes stress and strain proportional to each other
stress/strain |
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Term
| an object will only retain its shape if the stress on the object does not reach higher than |
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Definition
| the yield point, if it is greater than the yield point, this is what is called a fracture point, and the object will either break or be so strained it will never regain its shape again |
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Term
context: solids expand when heated
as their molecules absorb energy, what happens to their vibrations |
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Definition
| their vibrations need more space, and vibrate faster |
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