In a venturi tube the area A1 = 100cm^2, Velocity V1 = 10cm/sec. What is the velocity V2 at point 2 if the area A2 = 10cm^2? What is the flow in cc/sec?
A1 x V1 = A2 x V2
100 x 10 = 10 x X, solve for X
X = 100cm/sec
Flow = A1 x V1
100 x 10 = 1000cc/sec
What are the SI units of Tension? Remember T=PR/2. Where T = Tension, P = Pressure, R= Radius
Kg / (sec^2)
What is the apparent weight of a sphere that is 10Kg in mass with a radius of 0.1 meters? Volume of a sphere is (4/3)pi*r^3. Spc gravity of water is 1gm/cm^3 or 1000Kg/m^3.
10Kg = 10,000gm and 102gm = 1 newton
10,000 / 102 = 98 newtons
(4/3)pi10^3 = 4,188
4188 / 102gm = 41 newtons of water
So, 98 - 41 = 57 newtons to weight
Cyclopropane has a velocity of 1.0m/sec through a tube diameter of 1.0cm into a diameter of 0.01cm. What is the Velocity change? What is the Pressure drop? Cyclopropane density is 1.8kg/m^3.
1x10^4 m/sec, -9x10^7 pascals
As Velocity increases Pressure will Drop.
Force Equation (phAg)
pvg = pressure or phAg
p = Density
v = Volume (Ah or Area x Height)
g = Gravity
Flow Equations. 3 of them
V1 x A1 = Flow
Velocity x Area = Flow
(Mass or Volume) / Time
Pressure / Resistance = Flow
You are handed 5cc of 40mg/cc dopamine to mix in 245cc of NS. What is the final concentration in mcg/cc?
1. 40mg x 5cc = 200mg/cc
2. Convert to mcg 200mg x 1000mcg = 200,000mcg
3. 200,000mcg / 245cc NS = 816.32mcg/cc
You are ventilating a patient and you analog pressure gauge reads 20cm H2O. What is the pressure in pascals?
1. There are 1.36mmHg in 1mm H2O
2. 20cmH2O / 1.36mmHg = 14.7mmHg
3. There are 760mmHg in 1 atmosphere
4. 14.7mmHg / 760mmHg = 0.01934mmHg
5. There are 100,000 pascals in 1 atms
6. 0.01934 x 100,000 = 1934 pascals
Given Poiseuille's law:
Q = [(pir^4Delta P) / (8nl)]
What statement is true?
Flow is directly proportional to the 4th power of the radius.