physics formulas, memorize these?

[2010premed]

So I have my physics formula sheet from BR and I'm wondering if I should memorize Poseuille's principle Q=(pir^2/8nL)P1-P2
can someone explain this conceptually???

Also I have this turbulence formula: NR = 2pvR/n if Nr<2000 laminar flow if NR>2000 turbulent flow. Again should I memorize this and can someone please explain it conceptually? thanks

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[coyfish]

So I have my physics formula sheet from BR and I'm wondering if I should memorize Poseuille's principle Q=(pir^2/8nL)P1-P2
can someone explain this conceptually???

Also I have this turbulence formula: NR = 2pvR/n if Nr<2000 laminar flow if NR>2000 turbulent flow. Again should I memorize this and can someone please explain it conceptually? thanks

You have the r^2 when it should be r^4. That is the only thing I remember from that equation. Big equations are not likely to show up on the MCAT unless they are provided in the passage. It is up to you if you want to memorize it but the key thing to know is the r^4.

The formula I remember is Q=vA. Essentially both are saying the same thing. As you increase the area the flow rate (Q) increases. You can logically derive the NL part of the equation. As you increase the viscosity the flow rate will decrease . . . that makes sense. And as you increase the length of the pipe there will be more friction along the walls so the Q will decrease.

 

[2010premed]

thanks, this is great =)

Does anyone know what the second one means??

 

[fizzgig]

it's reynolds number and i wouldn't think we'd need it memorized. conceptually just know that if fluid goes faster or has less viscosity, it's more likely to be turbulent. the only reason i could see needing to know this would be realizing that a lot of the fluids formulas you've memorized require laminar flow as one of the assumptions you make.